Enable mouse-over popup for content linked under New Posts and New Profile Posts

Would be nifty if I didn't have to click on the entire link to read the info after (...) but instead hover over the link and the full title is available as a yellow popup box. I don't think that's currently supported, not in Chrome anyway, but I believe it would be easy to enable it. I think it is an alt true or false tag, been a while since I coded anything though.

Edit: I think they're called tooltips.