BoingBoing (which is just full of good stuff today) provides a pointer to the first Human-Computer Interface Rap at OK/Cancel:

After that generate a lot of designs
run them by some users even just 2 at a time
iterate and iterate and soon you'll oblitherate
any interfaces which are wack or inconsiderate

that will help you mitigate support costs or generate
website hit rates and orders. So check it:
you'll be taking profits instead of mounting losses
'Cause you brought us in at-the front of the process

But you should really listen to it to get the full effect.