After months of having my iPhone 3G not even last a day anymore, I decided to get a new battery. I settled on this one: http://www.dinodirect.com/NEW-1600mAh-Replacement-Internal-Battery-for-iPhone-3G/AFFID-15.html.
I soldered it together (the downside) and put it in the phone, but while putting connector 3 back (the flat ribbon cable), the clip seemingly disintegrated. So I ordered a new clip on eBay for $9 and it should be here shortly. I will write a guide for repair if I am successful.
Thankfully, Radioshack is two blocks away so I bought a 15/30 watt soldering iron, some thin .50 solder, and will make sure I don’t have caffeine jitters while I replace it.
If not, maybe I can review a repair service.