CRAPTASTIC PLASTIC -- Friends and I used to play this a lot, and we later hosted an Ice Bowl under these conditions. Every player brings one disc -- the worst or weirdest disc they can find -- and throws it in the mix. Let's assume four players, so let's say (as a good example) you've got a beat-to-hell Optimizer, a gnashed Epic, a destroyed Blunt Gumbputt and a brand-spanking fresh proto-Speed Demon. Each player starts with one of the discs and has to complete the hole with that disc, after hole one, discs rotate, etc... It makes for some frustrating holes, and the hardest part is when the discs are so different. An Optimizer is the flippiest roller I've ever used... the proto speed demon is so overstable I've given it to big-arm pros who can't put it more than 250' on the hardest S-curve they can throw. And trying to putt with any of these is ridiculous. However, it forces you to try shots you would never have imagined, and is a lot of fun to keep from playing seriously.
With the ICE BOWL we held, I think we had 16 people show, so we drew straws to pick groups of four, and each group had to throw the four discs that group had brought. Then for the second round, we seeded people based on how they placed relative to the people in their group in the first round, so that even if one group had "better" crap-discs than another, the fact that they shot lower didn't mean they all ended up on the lead card second round. For the second round we also seeded the discs based on relative crappiness, so that the people in the top group had the four discs voted the worst of what was brought, etc... Was incredibly fun.
If you need a low-key way to play with friends, this is a favorite.