I just got an iPhone 3G and had the AT&T store copy over all (in theory) my contacts from my Sprint Motorola Razr V3m over to my iPhone's SIM then import them. Alas, I found a lot of missing info, probably due to SIMs being very limited in what each entry can hold. Example: I had home and mobile # for someone, but only the home # made it over and got marked as mobile on the iPhone. So, rather than manually fixing and typing on the iPhone, I'd rather do it on the computer and sync it. iTunes for Windows gives the choices of address books for Yahoo, Google, Windows and Outlook. I'd imagine there could be some field mapping issues w/some one or more of them. I don't need anything too fancy (don't care about addresses, birthdays, anniversaries, etc.). It just needs to have the right names, numbers and phone # mappings. It should also be reliable and be able to handle a few contacts w/o last names.