Whenever I've asked, that's been pretty strongly recommended _against_. Clownfish differ - sometimes quite a bit - in their levels of aggression. Ocellaris, perculas and skunks are usually fairly mellow, but clarkiis, tomatoes and maroons can be genuinely harsh. (Heck, I often hear about clownfish ripping into their _people_!) In a big enough tank, I've seen it done - but how big is your tank?!
~Bruce, who asked about it in regards to his 220 gallon - and was told "not a good idea..."