When the iPhone 4G rolls out, are you going to wait till Summer 2011, or sell your 3GS on Ebay/Craigslist to offset the upgrade penalty? Odds are, the new one will be a substantial improvement over the 3GS, a complete upgrade, so patience might pay off, but I guess if you can sell your 3GS for a good price, there's really nothing wrong with constantly upgrading.