Instead of a Tracfone, get a (cingular/ATT) Gophone- Get it at walmart, and you can, if your trip goes longer, use it with a regular GSM simcard as a non-prepaid phone.
Or buy an UNLOCKED GSM phone at home, (Ebay is a good source) and when you get here buy a prepaid SIM card from a local wireless store- CIngular, and T mobile are both GSM, as well as alot of smaller carriers.
You might also try posting on Howard forums for more advice:
http://www.howardforums.com/
Happy Trails,
Lawrence