I just signed up for this contract…
Vodafone just changed their $29 cap for Nexus S with 2 month free access to $10 off for first 12 months. This means a saving of $120 instead of the original $58!
With moneybackco, you can get $84 back. If my calculations are right you pay only $20.50 per month. To me, it's quite a good deal even if the phone isn't the newest one out there…
They had this on offer just a week ago (expired 11/9). Then it changed to 2 months free, but looks like they've changed it back again.