If you mean transferring $ from your US bank account to your Peruvian bank account (dollars), we've found Xoom to be an easy, less expensive alternative to Western Union or MoneyGram and way less expensive than a bank to bank transfer. The first time you do it it takes longer due to the verification and security process.
Another alternative which is faster is to use Xoom to wire $ to the person in Peru and then just pick it up at the same bank where you intend to deposit it and deposit it on the spot. This is faster and can be accomplished in a few minutes.
Good luck! Feel free to pm me if you have further questions.