The circus has cum to town at Gay Sex Blog! Step right up!
I've never written about clown sex before, and there's a reason for that. I suspect that pornographic clowns are a porn niche in search of an audience. Is anyone out there really turned on by sexual clowns? If you are, let me know.
That said, I guess there is something kinky-perverted about clowns fucking. (Kind of like furries, where guys have their dicks sticking out of a bunny costume or a Big Bad Wolf getup.)
Then there is the Stop Clown Porn Movement, which seems to be an excuse to show clown porn, much of it heterosexual. They've got a Banned Link List, which serves as a list of places you should NOT go if you DON'T want to see clown porn. In other words — a clown porn link list!
The Porn Clown Posse has lots of stuff on their site, also veering toward the heterosexual, but hey, if you are that into clowns sexually, I'm sure you can find something hot.
One feature among many is Ouchy and Achtung! Play with Sharp Needles, which I guess qualifies as clown BDSM. (Ouchy The Clown also has his own site, where he sells clown schwag and is available for personal appearances. He appears to be GLBT-friendly, as well as Burning Man-friendly.)
Looking for actual clown porn DVD's? Here's one: Clown Fuckers from Sin City. You might have to go on EBay for it, but, as an aside, EBay has a new feature called Want It Now, which is a "reverse auction" where sellers bid against each other for a buyer for their product. Kinda cool!