In Benefits of Plain English URLs, the folks at Gadgetopia have added more fuel for the fire of why you should use beautiful URLs. For me, any two of the many reasons should enough to convince the maker or your CMS or weblog software to make nice URLs a default in their setup.
When picking URLs, we envison [sic] someone at the client’s firm reading the URL to someone over the phone. How easy is it going to be?
I especially like this idea of reading someone the URL over the phone and asking them to write it down, remember it, or type as you read. Great URL design and implementation makes this interaction painless and pleasant.