If you didn't read the contest announcement earlier in the week, checkout Linux Hardware Enthusiasts: Win Some $100 Amazon Gift Cards. That article covers all of the contest details, but it's quite easy; it basically comes down to running your own Phoronix Test Suite benchmarks, uploading them to OpenBenchmarking.org, and then sharing them with us to enter the contest via Facebook, Twitter, or Google+.
You're able to submit to the contest daily before it ends on 7 April. With being Amazon.com email gift certificates, the contest isn't limited to the US alone. Good luck!