I'm generally a sucker for a film that lures you in by its atmosphere, without telling you too much, letting the story evolve slowly, leaving the viewer with somewhere to go, something to figure out while watching. One Point O is that film, in spades.
It's yer basic sci fi thriller, with nanotechnology, mind control, kinky sex and seriously warped (but interesting, very interesting) characters at every turn. Jeremy Sisto, as the central character, makes it compelling in a subtle way, in that I really wanted to know what the #@%! was going on with him: was the whole thing in his mind, or was it happening in reality, or what? While the film doesn't spell everything out - which is a good thing, a very good thing - there's enough info that, by the end, the conscientious viewer can get the gist of what's transpired. I do recommend a second viewing, though - get the DVD, as I plan to do, since this one's not shown on cable that often.
I see this film as having tremendous cult appeal, where audience members dress accordingly and hover in a suspiciously extra-dark and oddly damp screening room, late at night. Also a good thing.