It will probably help others out...
If your a Perm Resident (green card). You do not need a Form I-131 Travel Document (passport for perm residents) to travel to, in my case Jamaica. Just need to show Green Card. And a Green Card will get to back into the USA.
Other foreign countrys maybe require a Travel Document (passport) to enter, BUT green card is the only requirement to return if traveling out the country for less than 1 year. Again this is for Green Card Holders.
If you google around... you will read false info that a Perm Resident requires a passport for example
http://answers.yahoo.com/question/index?qid=20080409212623AAPE2c5, but that is NOT true. So i'm out $385 for the Travel Doc.