Reading the data plans available in the UK makes me want to cry. I'm in France. Yes, that would make most people cry, but using the frankly strange dataplans over here makes me depressed. SFR's Pay and go has an offer; €69 for a dongle with 3Hrs usage (yes, you are charged by the minute - not megabyte). When you buy it, you have 14 days to post your proof of purchase, along with a copy of your passport, and your proof of residence back to SFR, or else they close your line.
It costs €39 (About £34?) for 15 hours (Fifteen hours) to recharge.
If you want to spring for a full 1 year subscription, you pay €49 per month, and you're limited to 2GB usage per month. You are NOT allowed to put the sim in your phone, NOT allowed to use a router, NOT allowed to use Skype, NOT allowed to use Xbox live nor Playstation online. etc etc.
Other companies such as Orange also charge per minute for pay and go, at a worse deal.
God, I miss the UK....

T Mobile sim only, 1 month contracts over £20 have free 1GB/mo internet included.

Contract

Tmobile - £7.50 pm 1Gb
£12.50 pm - 3Gb

Vodafone - £7.50 pm - 500mb
£15 pm - 3Gb

O2 - £7.34 - 500Mb

Orange - £7.34 - 500Mb
£9.79 -1Gb
New customers - (£4.89 per month for 500MB of anytime mobile internet access)

3 - Not sure?

Tmobile really seems the best (discounting 3 as I cant find separate internet info)

That's actually the best value-for-money offer in the UK market, imho. However, you still need to fork out over 400 quid for N900...

True but then you have the flexibility to upgrade when you want (ie before 2 years) and get a great price back for it on ebay :D

True but then you have the flexibility to upgrade when you want (ie before 2 years) and get a great price back for it on ebay

Isn't the free phone upgrades option only available on the 12/18/24 month contracts, and not the 30-day ones?

I'm probably just mixing up "upgrade" with "buying a new sim-free phone", and ebaying my current one.