We have many cross-site advertisements on the Stack Exchange network, highlighting questions, an Area51 proposed sites, and of course the per-site community promition ads etc. An example:
Is there any way to post such advertisements on my own site? Of course, ideally, I would love to earn revenue from such things, but even in the absence of the option for earning revenue, I would love the opportunity to help promote my favorite/most relevant SE sites on my blog.
Is such an advertising channel available? If not, I guess this is a feature request. :)
EDIT: I've found that it's simple to extract the relevant JS snippet to produce the same ads as found on the various sites, but for this to be relevant to me, I would need a) permission to do so from SE, and b) the ability to display ads/questions only from the site(s) I choose, rather than from the entire SE network.