Here's a tip:
If you are trying to use GPS with arduino, consider using the TinyGPS library. It has a reasonably small footprint and seems relatively easy to use. I am going to use it when I get my GPS hooked up with my autopilot software. Should make things much easier than having to manually parse the data string.
Side note: For some reason, the TinyGPS website is sometimes down... or it might be slow loading.
Zachary