Test Environment :
iPhoneModem (Mac and iPhone applications – Both are required)
Macbook Pro , OS X Leopard 10.5.5
iPhone 2.1 (iPhone is now really Usable!)
Using Safari on my MBP as other apps need hacks to enable them.
ATT 3G / EDGE network (In Train (NJ-NYC) – Slight fluctuations, iPhoneModem very stable!)

We all know that ATT caps iPhone’s data capabilities at 1.4 Mbps but that is just enough for using it as a modem though all I can use is Safari for now. I am sure other applications can be used by configuring proxies …