I have a few idea-
1. Save your cash.
2.Donate in charity.
3.Invest in something, share markets etc.
4. Ipod 5g.
5.Upgrade your rig.
6. Buy games for your rig.
7. Buy accessories like headphones, KB etc.
8.Buy bicycle/ exercise equipment and stay healthy.
9.Spend the money to decorate your room.
10.Take it and shove it up your piggy bank....(didnt expect that did you?)
11.Donate to your favorite sites/buy some premium accounts on sites.....like media fire etc. Weren't expecting that were you?
12.Get a good internet connection.
13.Buy some gifts for your parents/relatives. They will be really happy. Or buy gifts for poor kids/people.The happiness you would get would be greater than all things mentioned above.
The donation seems to be great if you dont feel any need to buy something.