Here's how it works: you rent the handset for a year, rather than being weighed down with it for an 18- or 24-month contract. There's no upfront cost for the device, but you do have to return it at the end of the lease period. O2 has some stern words of warning for anyone who's ever got a bit careless with their phone, too.
The caveat reads: "With O2 Lease, the phone isn't yours and if you don't return it in satisfactory condition at the end of your lease, you may have to pay substantial charges." So bad news if you've made a habit of getting drunk and dropping your phone in the loo.
So what's the tariff like? You get 750 minutes per month, unlimited texts and 500MB data, with unlimited UK Wi-Fi, tethering and 20 UK picture messages. O2 will insure the phone too. For the privilege, you pay £55 per month for the 16GB iPhone 4S, or £65 per month for the 32GB.
Normally if you were taking out an iPhone 4S for 12 months on O2, you'd pay between £21 and £62 per month, with data ranging from £3 to £10 extra.
The 750 minutes per month is a limited offer, going down to 600 minutes according to O2's terms and conditions, though there's no word on when that'll happen.
So, what do you reckon? A good deal? Or is it too expensive just to avoid a longer contract? Would you rather keep the same phone longer than a year? Let us know in the comments below or over on our Facebook page.