I don't find these domains clever at all. They're impossible to remember, even del.icio.us is difficult to type in. That's why they bought delicious.com as well.
I just tried it; thought I found a clever domain name that ended with .ge; struggled to find somewhere to register an international domain name (anyone know of a good place?); found out .ge is the domain for Georgia; found out that the the <i>"administrative contact and the technical contact must reside in Georgia"</i>; game over. This is going to be harder than I thought.