Google actually has a contact system built into Google Mail. These are used just about everywhere, but most importantly you can use Google to synchronize contacts in Mac Address Book, iPhone and maybe even the Blackberry.
You unfortunately need third party tools to then take the contacts and push them to your iPhone (Nuviosync) and Address Book. "Spanning Sync":http://blog.spanningsync.com/2008/04/video-preview-s.html does Contact and Calendar sync for Google, although Calendar is obsolete with the CalDAV connection directly. "ABGMerge":http://iboughtamac.com/2007/04/04/keeping-gmail-cell-phone-contacts-and-apples-address-book-in-sync/
The sad thing is that "Apple":http://googlemac.blogspot.com/2008/05/mac-os-x-1053-sync-google-contacts.html added direct sync from Address Book to Google Contacts in 10.5.3, but this "only":http://digitalapplejuice.com/sync-with-google-contacts-in-1053-not/ works when you sync with something manual, like MobileMe or even another iPod. Still, it seems silly to be manual. Duh. How silly is that.
But how do you get the contacts up there to being with. Here is how:
You can export your Outlook Contacts as a Comma Separated Values (.csv) file and then import your contacts into your Gmail account.
Export Outlook Contacts
1. In Outlook, on the File menu, click Import and Export.
2. Click Export to a file, and then click Next.
3. Click Comma Separated Values (Windows), and then click Next.
4. In the folder list, click the Contacts folder, and then click Next.
5. Browse to the folder where you want to save the contacts as a .csv file.
6. Type a name for the exported file, and then click OK.
7. Click Next.
8. Click Finish.
Import Contacts into Google Gmail
1. Log on to Gmail, and then click Contacts at the top of the page.
The Contacts list opens in a new window.
2. Click Import Contacts.
3. Click Browse, and then navigate to the .csv file that you created in the "Export Outlook Contacts" section of this article.
4. Select the file, and then click Import Contacts.
After your contacts are imported, a dialog box appears and displays the total number of contacts imported.
As an aside, if our using Entourage, it only produce tab separate and not CSV files, so its pretty inconvenient. Find a Windows machine and use Outlook for the sync.
If you are using Mac Address Book, then "A to G":http://bborofka.com/atog/ exports from Apple to Google. Clever eh?