I'm with giffgaff and for £10 a month sim only I get unlimited data OR 1GB of data that I can use via a wifi spot on my laptop + unlimited texts + 500 minutes , signal coverage is good since they run over O2 apart from a couple of iffy network failures when they launched , top network though and for a little bit of help on the forum you can get the contract free
I'm with giffgaff and for £10 a month sim only I get unlimited data OR 1GB of data that I can use via a wifi spot on my laptop + unlimited texts + 500 minutes , signal coverage is good since they run over O2 apart from a couple of iffy network failures when they launched , top network though and for a little bit of help on the forum you can get the contract free