If you go into Gmail and hit contacts, and then “export” in the upper right hand corner, a menu pops up with a list of different ways to export your contact list. I guess you would want the Outlook CSV choice, or maybe vCard? doing either one will download a little file full of the contacts, which you should be able to point your iphone towards? Not owning an iPhone or using Exchange, after that initial step of hitting “export” i don’t know where you should go, but my hope is that the contact-list-file is the right thing.