I found though I'm not sure that this is always true. That the cable that comes with an iPod will sync my phone and charge it when plugged into my computer, but doesn't work with the plug that comes with the iPhone. But the cable that comes with the iPhone will do it all.
I've had no problems at all interchanging iPod and iPhone USB cables. If you have an older firewire one, it won't work but apart from that I find I can use any iPod cable with my iPhone and vice-versa. This is into the wall charger, an in-car USB charger or my computer
I'm pretty sure all iPod-Connector (30-pin) to USB cables are fully compatible.
If it can plug in, it should work with your iPhone / iPod. It's when you start getting into weird accesorries (in-Car, mini-stereo, etc.) that things can get weird.