Remember that great 80's arcade game, Joust? Abramelin Wolfe and I were talking about it, and he mentioned he wanted to recreate the experience in SL. I started making a bird right away!
The result is that we came up with a truly fun multiplayer game that plays a lot like Joust but with the added fun of 3D. You can play for free here:
http://slurl.com/secondlife/Moon%20Shadow/128/128/36
All you need is one or more friends and a sense of adventure. Competitiveness helps too! When you're done kicking butt, you can see your uberness ranking on www.skyjoust.com
The mounts are available to buy separately too so you may ride them or joust anywhere, and you may also purchase the event version there which includes 2 kinds of bird rezzers (one rezzes free birds and one that pays the owner when a player rezzes a bird) and a copy/mod arena with it's own nifty rezzer system for easy set-up. The arena comes in both megaprim or standard prim versions.
I hope that didn't sound too much like an advertisement, we seriously just want people to come over and play for free so we have other folks to play with. It's terribly addictive!
Hope to see you there!