I was looking at one of these, even at

Do be careful about these unsolicited calls from mobile phine companies. People have been cought out by them before. People having Orange Contracts have been rung up by Orange trying to get them onto another Orange contract. Only problem was it wasn’t Orange it was someone else pretending to be Orange. This happens with all the mobile phone compinies. The best thing is to check out any such deal with the company direct by going to their website and/or ringing up your normal customer services number to check the deal out properly and make sure it exists and the terms are the same and that there are no hidden catches!

With this deal, I would check what happens if you go over the 1Gb limit. You might be in for a shock. Some people have had phonebills for thousands of pounds for going over data caps.

This is a general offer to all existing customers, and on all levels, 1, 3 & 7GB per month (18/24 month plans, but a lifetime deal so long as you stay on contract mobile).
http://www.three.co.uk/personal/products_services_/mobile_broadband_/existing_customers.omp

Given the extortionate penalty rate of 10p per MB (that means

Don’t hesitate. I have one of these — I pay

It’s only the Ts&Cs that stop you connecting the laptop to the phone and using the 1GB that you’re already paying for and not using up. There’s no technical block.