I currently have ST prepaid service with a Samsung SGH-t401g. The internet is very limited on the small screen so I don't even use it very much. It frustrates me. Now I am in Houston, TX and have a larger market to choose from with the prepaid services. I want the cheapest unlimited plan with a new phone (when I can afford it). I'm also wondering if I can use my current phone with a different service until I get a new one? And if so, which services?