I haven't, but my husband has...though it wasn't on an organized dating site. He actually met me on the Myspace poker chat, along with many other good friends that we have to this day. He was 49 at the time, and I think he'd tell you that it worked out pretty well ;). I've heard of a lot of mixed results on dating sites, I think primarily because everyone on there is actively looking and so many may not be very upfront and honest about themselves. When you're socializing for friendship people tend to be a lot more open, and then you never know when you might find someone that can be more than a friend.