Harvey Birdman is a very silly show. Even sillier than 'Sealab 2021', which employs the same concept of satirising 1960's Hanna Barbera cartoons. Harvey Birdman is pretty funny, though I must admit the charm wears off rather quickly.
All the same, it's hard not to like a show that manages to parody The Flintstones and The Sopranos in the same episode, at the same time. 'Harvey Birdman' only turned up recently on Australian TV, unfortunately sandwiched in the middle of the otherwise execrable 'Happy Tree Friends', and has become an instant cult favourite. Unfortunately, due to the extent that I detest most of the rest of the segments which it gets shoved in amongst, I haven't caught many episodes and am going to order the DVD set which comes out in April 2005.
(edit. I now have the boxed set, and have to admit to being a little disappointed. Not all the eps are that good)
Harvey himself is the old Birdman superhero character from the 60's, and his clients consist of cartoon characters from the same era - Hanna Barbera must have just sold them the rights to use every one of their characters and given them free reign. This leads to court cases involving Shaggy and Scooby Doo being busted for possession, The Jetsons sueing The Past for global warming, and Scrappy-Doo being hurled out of the frame (a couple of moments there which some of us have waited decades to see!)