I just read an article in the Los Angeles Times Online (linked to from Drudge Report) about a gay porn actor (Derik Chambers) that just tested positive for HIV. I think its significant because he claims he's only had anal sex with condoms and oral sex without comdoms in his acting scenes. He claims he only has sex with his girlfriend in private life, and she tests negative for HIV. He gets tested monthly in order to be allowed to act in porn; so it's easier to determin0e where he contracted the infection.

This looks like a case of HIV transmission from oral sex. Its anecdotal, but I think its probably a warning sign for hobbiests who engage in uncovered oral sex.  

Sorry about not posting links; I'm technologically challenged.