iPhone has a lot of disadvantages as a Phone - Outdated (written before ios 4).
1 - Blue Tooth only works with other iPhones
2 - Contacts cant be saved onto the SIM card
3 - Mobile Carriers had to make work arounds for Delivery report
4 - Can't send Business cards
5 - Call forwarding only has one flavour - unconditional
6 - Cant make ring tones per Contact groups
7 - Cell Info Display not available
8 - individual Call Logs can't be deleted
If you have any comments just send me an email!