Well, here's the thing... you said you don't want sites that are built for online dating, but rather, hooking up. Like, adult friend finder type sites? It really depends on what you're looking for. I'd say that dating sites are usually for those looking for a relationship of some sort, as dating usually implies. Hook-up sites are for those who want the benefits of relationships without the work that comes along with forming and maintaining one. Dating sites can lead to something long term, whereas hook-up sites seem to be a quick fix without committment.
I don't know. I'm not one for non-committal hook-ups and moving on as if nothing happens. It's hard to "hook up" without something emotional taking place. I'm sure it's possible, but that's just not my view on physical parts of relationships. I think that emotion/physicality go hand in hand, so to speak. Then again, everyone has their own views on this.
Again, it really boils down to what you want. I just don't think many join actual dating sites that do compatibility profiles and so forth if all they're looking for is a quickie; otherwise, they wouldn't waste their time selling their personality and relationship qualities. So, do what you will, but make sure the person on the opposite end is on the same page as you are; it wouldn't be cool to make someone who is looking for a relationship think you're doing the same, when you're just looking for a piece. Not that I'm saying you'd do this of course, but just make sure both parties have a solid understanding. And, a word of advice... these situations can get messy.
