Hi Amani-

We just started using Language Line Solutions.  They offer many, many languages that when you contact the 1-800 number, they can choose their language and then you are connected to an interpreter. You are only charged when you use the service.  Their email is pi@languageline.com

Amani, I've used Vocalink for the past few years, and they've done a wonderful job with Spanish/English translations. http://vocalink.net/ or call 877.492.7754