On the iPhone 3g goto:
2. Mail, Contacts, Calendars
3. Add Account
5. Under Contacts Add CarDAV Account
6. Server put in p02-contacts.icloud.com
7. User Name your iCloud email (example: email@example.com)
8. Password your iCloud password
11. DONE.......You may have to enter your password again. Open Contacts, it may take a few minutes to sync.