Black Label Ads.com (use to be AVN). It's adbrite's adult links. I think you can also use the same API for non-adult ads if you have a non-adult web site.

I think their system puts up sort of a preroll or postroll that is a full ad block, but I'm not sure. I haven't even thought about where to begin adding to to vshare, not sure if I could figure it out.