Is there anyway I can get my phones Internet to work? I have unlocked Sidekick 3 on optus prepaid

Contact Optus and make sure you have a Data Plan added on your account. If you don't and they have to add it, it may take up to 24 hours to be able to access the internet. (And, make sure when you call Optus ask them to check whether your phone is compatible with their system to use Data service.)

If, when you call Optus, you find out that you already pay for Internet Data Service and are not able to use it, request to speak with Tech Support. They'll troubleshoot the problem and have you up and running in no time.