Well, sorry to post here, but it would seem someone is eager to close stuff on sight.

http://forum.lowyat.net/index.php?showtopic=425493&hl=

Whoever closed that thread, when I said 3 (Australia btw, can't say for UK) will unlock it for you, what I meant was they will provide the unlocking code. It may not apply to 6630 or 6680 or 6280, but it definitely will work for 6288.

To the TS of the locked topic, if you are reading this, just call 3 customer care, they will ask you why you wanna unlock (I would say that is my business, but let's not be rude and just say your main phone is better like n95 or something) then he/she will ask for your phone serial number, then provide the unlocking code. The firmware is still 3's, but you can now use it on any network.