Developers rejoice! Xcode finally submits your binaries to the App Store in multi-threading, allowing you to continue to work with it while you upload your apps. This has been a feature I’ve been waiting for ever since we started working with iPhone apps: back when the App loader was in its early stages, we were… →
iTunes and Xcode 3.2.3 do not recognize iPhone on Mac OS X 10.6
Before wasting too much time messing with cables and blaming USB ports (like I did), check on Apple’s Software Update if the iPhone SDK Compatibility Update 1.0 is there for you to install. The solution to your problem is just a handful of kilobytes and one restart away :)