Here are the per capita results (full data and sources listed below). Update: @Pang has produced a visualization: http://jsfiddle.net/T8m4s/embedded/result/ -- Snapshot here:

Note that California doesn't even make it onto the top 10 (it ranks at 13th place), and New York just barely makes cut for top 10.
- Washington DC [8.2%]
- Washington State [4.8%]
- Massachusetts [4.5%]
- Utah [3.8%]
- Oregon [3.4%]
- Colorado [3.3%]
- New Hampshire [3.2%]
- Minnesota [3.0%]
- Rhode Island [3.0%]
- New York [2.8%]
- Virginia [2.8%]
- Maryland [2.5%]
- California [2.5%]
- Nebraska [2.4%]
- Wisconsin [2.3%]
- Arizona [2.2%]
- Pennsylvania [2.2%]
- Idaho [2.0%]
- Kansas [1.9%]
- New Jersey [1.9%]
- Iowa [1.9%]
- Connecticut [1.8%]
- Illinois [1.8%]
- Ohio [1.7%]
- Wyoming [1.7%]
- Missouri [1.7%]
- Michigan [1.7%]
- Alaska [1.6%]
- Maine [1.5%]
- North Carolina [1.5%]
- Montana [1.4%]
- Georgia [1.3%]
- Florida [1.3%]
- Texas [1.3%]
- Vermont [1.3%]
- Tennessee [1.3%]
- Indiana [1.2%]
- South Dakota [1.2%]
- North Dakota [1.1%]
- Nevada [1.1%]
- South Carolina [1.0%]
- Oklahoma [0.9%]
- New Mexico [0.9%]
- Alabama [0.8%]
- Arkansas [0.8%]
- Kentucky [0.8%]
- Delaware [0.7%]
- Louisiana [0.6%]
- Mississippi [0.5%]
- Hawaii [0.4%]
- West Virginia [0.3%]
- Puerto Rico [0.2%]
Note this is 52 items because it includes Washington DC and Puerto Rico -- which, interestingly, rank at the very top and very bottom respectively. My theory on DC is that it is all city so white collar skilled professions will be more common, and my theory on Puerto Rico is the language barrier, Spanish being the dominant official language there.
Raw stack exchange data from https://www.surveymonkey.com/sr.aspx?sm=vU4rF_2bPVQaftSo1s69bGGbvMPXp7ktcfSHiDFP_2bM5qw_3d:
Alabama - 20, Alaska - 6, Arizona - 74, Arkansas - 12, California - 471, Colorado - 87, Connecticut - 33, Delaware - 3, Florida - 126, Georgia - 66, Hawaii - 3, Idaho - 16, Illinois - 114, Indiana - 41, Iowa - 29, Kansas - 28, Kentucky - 17, Louisiana - 13, Maine - 10, Maryland - 75, Massachusetts - 149, Michigan - 85, Minnesota - 82, Mississippi - 7, Missouri - 52, Montana - 7, Nebraska - 22, Nevada - 15, New Hampshire - 21, New Jersey - 85, New Mexico - 9, New York - 280, North Carolina - 72, North Dakota - 4, Ohio - 101, Oklahoma - 18, Oregon - 66, Pennsylvania - 141, Puerto Rico - 3, Rhode Island - 16, South Carolina - 24, South Dakota - 5, Tennessee - 41, Texas - 169, Utah - 55, Vermont - 4, Virginia - 114, Washington - 168, Washington DC - 26, West Virginia - 3, Wisconsin - 66, Wyoming - 5
Raw census projection data from http://www.census.gov/popest/data/state/totals/2012/tables/NST-EST2012-01.csv:
Alabama - 4822023, Alaska - 731449, Arizona - 6553255, Arkansas - 2949131, California - 38041430, Colorado - 5187582, Connecticut - 3590347, Delaware - 917092, Florida - 19317568, Georgia - 9919945, Hawaii - 1392313, Idaho - 1595728, Illinois - 12875255, Indiana - 6537334, Iowa - 3074186, Kansas - 2885905, Kentucky - 4380415, Louisiana - 4601893, Maine - 1329192, Maryland - 5884563, Massachusetts - 6646144, Michigan - 9883360, Minnesota - 5379139, Mississippi - 2984926, Missouri - 6021988, Montana - 1005141, Nebraska - 1855525, Nevada - 2758931, New Hampshire - 1320718, New Jersey - 8864590, New Mexico - 2085538, New York - 19570261, North Carolina - 9752073, North Dakota - 699628, Ohio - 11544225, Oklahoma - 3814820, Oregon - 3899353, Pennsylvania - 12763536, Rhode Island - 1050292, South Carolina - 4723723, South Dakota - 833354, Tennessee - 6456243, Texas - 26059203, Utah - 2855287, Vermont - 626011, Virginia - 8185867, Washington - 6897012, Washington DC - 632323, West Virginia - 1855413, Wisconsin - 5726398, Wyoming - 576412, Puerto Rico - 3667084
Per-capita * 1,000,000 (i.e. number of SO responses per million state residents):
Alabama - 4.147636790616718, Alaska - 8.202895895681038, Arizona - 11.292098354176666, Arkansas - 4.068995239614653, California - 12.381238034427202, Colorado - 16.770819237170613, Connecticut - 9.191312148937136, Delaware - 3.2712094315510334, Florida - 6.5225601897713, Georgia - 6.653262694500826, Hawaii - 2.1546879185930172, Idaho - 10.026771479851202, Illinois - 8.854193567428373, Indiana - 6.271669766299228, Iowa - 9.43339147338515, Kansas - 9.702329078746528, Kentucky - 3.8809108269421957, Louisiana - 2.8249244387038117, Maine - 7.5233675797025565, Maryland - 12.745211496588617, Massachusetts - 22.419014694836584, Michigan - 8.600314063233556, Minnesota - 15.244075306475628, Mississippi - 2.345116763363648, Missouri - 8.635022188685863, Montana - 6.964197062899633, Nebraska - 11.856482666630738, Nevada - 5.436888418014078, New Hampshire - 15.900442032288499, New Jersey - 9.588711942684322, New Mexico - 4.315433235932407, New York - 14.307422880052544, North Carolina - 7.383045635527954, North Dakota - 5.717324063645251, Ohio - 8.748963226201845, Oklahoma - 4.718440188527899, Oregon - 16.92588488397947, Pennsylvania - 11.04709541305795, Puerto Rico - 0.8180887048128703, Rhode Island - 15.233858774512232, South Carolina - 5.080738222795875, South Dakota - 5.999851203690148, Tennessee - 6.350442509676293, Texas - 6.485232875310883, Utah - 19.262511964646638, Vermont - 6.389664079385186, Virginia - 13.926441756261127, Washington - 24.358374322097742, Washington DC - 41.118225969955226, West Virginia - 1.6168906868713326, Wisconsin - 11.525569825918492, Wyoming - 8.674350985059299
Percentage based on last result set (i.e. percentage of SO respondents normalized to population size):
Alabama - 0.824721537170129, Alaska - 1.6310745742340413, Arizona - 2.2453356411538934, Arkansas - 0.8090843480665424, California - 2.4619016030822145, Colorado - 3.3347316843587764, Connecticut - 1.827612557886197, Delaware - 0.6504515720608812, Florida - 1.2969544194811282, Georgia - 1.322943476877953, Hawaii - 0.4284409706182859, Idaho - 1.9937363865669924, Illinois - 1.7605794571625484, Indiana - 1.2470670387501877, Iowa - 1.8757479281354774, Kansas - 1.9292238341738914, Kentucky - 0.7716853968642833, Louisiana - 0.5617116789849995, Maine - 1.4959562729950668, Maryland - 2.534274563482699, Massachusetts - 4.457826274179643, Michigan - 1.7100977237018886, Minnesota - 3.031151919554754, Mississippi - 0.4663060917725937, Missouri - 1.7169991328706176, Montana - 1.3847700743382283, Nebraska - 2.3575585577735083, Nevada - 1.0810780210241895, New Hampshire - 3.1616647398393933, New Jersey - 1.9066320538825035, New Mexico - 0.8580864023448015, New York - 2.8449067230945992, North Carolina - 1.4680544736474985, North Dakota - 1.1368402124642574, Ohio - 1.7396553181517227, Oklahoma - 0.9382208331577232, Oregon - 3.365565140867746, Pennsylvania - 2.1966189351328276, Puerto Rico - 0.16266983061322227, Rhode Island - 3.0291204509448555, South Carolina - 1.0102606492793207, South Dakota - 1.1930182793955861, Tennessee - 1.262730314317618, Texas - 1.289532207336161, Utah - 3.8301831330026452, Vermont - 1.2705291826596392, Virginia - 2.7691519369578557, Washington - 4.84345108504518, Washington DC - 8.17600195956597, West Virginia - 0.3215046639882644, Wisconsin - 2.291759414685823, Wyoming - 1.7248193223031953
Previous result set sorted by percentage descending:
Washington DC - 8.17600195956597, Washington - 4.84345108504518, Massachusetts - 4.457826274179643, Utah - 3.8301831330026452, Oregon - 3.365565140867746, Colorado - 3.3347316843587764, New Hampshire - 3.1616647398393933, Minnesota - 3.031151919554754, Rhode Island - 3.0291204509448555, New York - 2.8449067230945992, Virginia - 2.7691519369578557, Maryland - 2.534274563482699, California - 2.4619016030822145, Nebraska - 2.3575585577735083, Wisconsin - 2.291759414685823, Arizona - 2.2453356411538934, Pennsylvania - 2.1966189351328276, Idaho - 1.9937363865669924, Kansas - 1.9292238341738914, New Jersey - 1.9066320538825035, Iowa - 1.8757479281354774, Connecticut - 1.827612557886197, Illinois - 1.7605794571625484, Ohio - 1.7396553181517227, Wyoming - 1.7248193223031953, Missouri - 1.7169991328706176, Michigan - 1.7100977237018886, Alaska - 1.6310745742340413, Maine - 1.4959562729950668, North Carolina - 1.4680544736474985, Montana - 1.3847700743382283, Georgia - 1.322943476877953, Florida - 1.2969544194811282, Texas - 1.289532207336161, Vermont - 1.2705291826596392, Tennessee - 1.262730314317618, Indiana - 1.2470670387501877, South Dakota - 1.1930182793955861, North Dakota - 1.1368402124642574, Nevada - 1.0810780210241895, South Carolina - 1.0102606492793207, Oklahoma - 0.9382208331577232, New Mexico - 0.8580864023448015, Alabama - 0.824721537170129, Arkansas - 0.8090843480665424, Kentucky - 0.7716853968642833, Delaware - 0.6504515720608812, Louisiana - 0.5617116789849995, Mississippi - 0.4663060917725937, Hawaii - 0.4284409706182859, West Virginia - 0.3215046639882644, Puerto Rico - 0.16266983061322227