Note that this doesn't exist. Only local law could force sites to implement this, and afaik only the UK had a defunct specification of something like that they did'nt even follow for government pages. So, just the usual law craze.

> Is there a nice JS lib to detect and put up an unobtrusive hover-over popup in the bottom corner or something?

Well, I don't know if this is nice enough as I didn't use it, but it looks ok: http://sitebeam.net/cookieconsent/