I have an iPhone on a FamilyTalk plan and I am eligible for an upgrade in June 2010. However, I've been thinking about switching to a Bold. I was wondering if it was even possible for me to switch at this point, earlier than I am eligible? Could I just buy an unlocked Blackberry from somewhere and put my SIM card in it and change the data plan from iPhone to smartphone? Or am I locked into an iPhone plan? Thanks.