Depends. What are your interests? If you like gaming, I'd suggest upgrading your graphics card if you need to, but $160 really won't get you far in that category.
On the other hand, you can always save it up and buy something really nice - maybe a new computer. ;o
Buy condoms. Fill a backpack with condoms. Go on a sex spree = Reputation of a sex god among those who know about what this mysterious back contains - even if you didn't get laid-
Profit!