Can I specify multiple tags to search for just the questions that I have asked that contain those tags in my profile?
Seems like it'd be useful.
Winces expecting to be shot down over this...
If you search for "user:me [tag]" you'll get all the questions you've asked with that tag. Unfortunately you'll get all the answers you've posted as well. Though the sort by relevance seems to list the questions first (at least it did for me).
You'll have to enter the tags yourself though. There's no built-in way to get at that information. You could probably write a Greasemonkey script though.
For the low-down on searches see the search page.