I had good luck with these at my wedding. Instead of disposable cameras, I put cheap digital cameras. It didn't take long for guests to realise that the pictures were appearing on a large tv, in a sideshow. People got a lot more creative when they realised they would be seen quickly, not weeks later.
I managed to get them working without proprietary software, too. The onboard script logged into WiFi and uploaded the photos over ftp.
Given their size and the level of tech at the time, it was pretty impressive.
We also set up an excellent photo booth with the same setup.
A DSLR, on a tripod, a cheap remote trigger, and some photography lamps. We used drapes to box it off a bit. Throw in some inflatable props, and let the kids/drunks make it awesome.
The photos on the TV just encouraged others to join in the fun.