[sorbits]

URLs do not allow unicode but most user agents support http://en.wikipedia.org/wiki/Internationalized_domain_name

That said, non-ASCII URLs suck because not everyone can type them. Imagine being a tourist in Tokyo who has to lookup a restaurant on your laptop or having to lookup the product page for this gadget you bought in China…

[nanotone]

Right. As I noted above, it's absolutely not acceptable for some situations, particularly those where you want lost or confused people to look you up. But I can still think of plenty of other situations, and was merely pointing out the disparity between the number of Unicode URLs I've encountered and the number I'd expect to have encountered, given all the possibilities.