Today, O2 is announcing new tariffs (note that in UK jargon we say "tariff" instead of "plan") across the board, for both its subsidized handset contracts and its SIM-only deals. The full details are here, but the important details for iPhone owners are:
Tethering is now completely free. If you have a 1 GB data allocation, then it doesn't matter if you use that data on the phone or on a connected device -- it's all charged the same.
Data allocations are now tiered separately to your base plan. 100 MB of data is £3/month, 500 MB is £6 and 1 GB is £10.
The basic 300 min voice / unlimited SMS / 500 MB tariff is £37 per month with an 18 month subsidized handset deal. If you commit to a 24 month contract, you can deduct £5 per month. This used to cost £30.64 per month (Google Cache of the old page).
The same tariff structure on a 1-month-notice SIM-only deal is £21.50 per month (previously, this was £20.43). If you commit to a 12 month contract, you get twice as many voice minutes.
Upgrading customers can now choose 12 month contract lengths, meaning you can get each new iPhone release when it comes out. Previously, most people were on 18 month contracts, which didn't sync up very well with annual iPhone refreshes.
