I’ve had the iPhone 3G since it first came out. I camped out the night before, #2 in line for 15+ hours. I love my iPhone, so naturally my obsession with the device led me to jailbreak it. I’m running 2.2.1 software on there (haven’t "unlocked" it yet since I’m on AT&T for a long time), but it is jailbroken.
I’ve used PdaNet quite a bit and just recently, they released desktop software (XP/Vista only right now) that allows you to simply plug in your iPhone via USB and "pipe" the 3G Internet connection directly into your desktop or laptop. This is quite handy as you can turn off WIFI which will save quite a bit of power/heat vs the old way of tethering and also serves to charge your iPhone while sipping from its Internet connection!
About a week ago, the campus apartment Time-Warner internet here slowed to a crawl. It went from a typical 1.5Mbps connection to less than 100Kbps with huge latency spikes. I became fed up with this and decided to give the newest version of PdaNet a try.