O2 Mobile Broadband 3GB gives you a decent monthly data allowance, along with a free USB modem and no costs to pay on top of the monthly fee.

O2 Mobile Broadband is capable of download speeds of up to 3.6Mbps, though when the 3G network is upgraded in the future the USB modem is ready for download speeds of 7.2Mbps.
This package also gives you access to thousands of Wi-Fi hotspots around the UK, with unlimited wireless minutes which let you get connected without eating into the data allowance.
You will need to commit for 18 months in order to take advantage of this deal and it is worth checking out the O2 coverage map to see if mobile broadband is available in your area.
Check O2 Mobile Broadband Coverage in your area »