Second life is a fun, addictive game that can be as cheap or as expensive as you want it to be. Since users are encouraged to create modifications/additions/etc. there is a growing movement striving to see how Second Life could help educators. I'm not convinced, but that's just my opinion.
That being said, it's still addictive.
Here's some sites that have dissenting opinions:
- Pathfinder Linden is a Second Life employee who focusses on working with educators.
- The Second Life Education Community isn't too shabby, either.
- They even have an education wiki.
- Art and Language Arts teacher Bre Pettis is having a grand old time meeting movers, shakers, & makers.
- Ed Tech Talk # 45 toured Second Life about a month after I joined.