The rumor mill is pretty confident there will be a new iPhone announced on September 12, 2012. I knew I was eligible for an upgrade and wanted to get the new iPhone when it came out. What to do with the old iPhone? I checked gazelle.com for their prices on an unlocked iPhone 4, about $172 for good condition at the time I checked. But eBay had them going well north of $300.
So, I priced my iPhone 4, which I thought was in very good condition, at $350 Buy It Now / $250 auction reserve. BAM! Sold in 35 minutes.
Now, what do I do for a phone until I get the new iPhone? Hmn... I have an old Samsung BlackJack II locked to the AT&T network, that should work. Except for the size of the SIM - the iPhone 4 uses a micro SIM, and the BlackJack used a full-sized SIM. I had a dead, previously used AT&T standard-sized SIM from yet another phone. I decided to cut the full-sized SIM into a kind of tray adapter for the micro SIM. There are actual commercial products like this available on Amazon, but I didn't want to wait for shipping.
First, line up the contacts of the micro SIM approximately where the same contacts are on the full-sized one. Draw an outline for cutting, I used a fine point Sharpie. This doesn't have to be very precise, just an opening big enough to hold the micro SIM. Then, using a box cutter or Xacto knife, first carefully score the outline all the way around. Then slowly and carefully cut deeper into the outline. Work slowly, you don't want to break the plastic. Add Scotch tape to hold the micro SIM in place. The whole process should take about 15 minutes.