The approach of Douglas Sellers about testing their AJAX heavy system really sounded to me as an excellent idea. I can imagine in the future this being adopted by more and more web systems, as they embrace javascript for building RIAs more and more.

Essentially they have built a DSL on top of selenium using ruby (yay), for testing the AJAX stuff on their page, aiming at easiness to write the tests, trading the complexity of writing the tests for the complexity of the DSL itself, trying even for the non technical people on the company to write their own tests.

Really recommended for a fresh and no nonsense view on testing.