I sent off my 3gs to Amazon, no problems there. But... I have to have some kind of phone for work. I bought a cheap gophone to use...can I just pop my SIM in and use it for the next few days? Will it screw up anything? I'm mainly worried about somehow losing my text plan and unlimited data. I mean, can they take it away if they see I have a different phone? Even if for only a few days? Help!