I'm running a contest/giveaway in my new blog where you could easily get a Google Wave invitation (I've seen guys even selling invitations but you can get it for free easily).
All you have to do is:
1. Tweet about this giveaway/contest
2. Digg this giveaway/contest
3. Share this page on Facebook.
4. Subscribe to the blog
5. Follow @Anticrank on Twitter
You can check this out for more information: http://www.anticrank.com/2009/12/25-...ions-giveaway/
This contest/giveaway doesn't have a timeframe. It will end when all the invitations finish.
Cheers and good luck,