A cheap used Thinkpad T530 from ebay.
I really didn't expect it to be great quality as it's quite old and all I needed was a laptop so I could sit in another room and work on a project while my main desktop was being used by the kids. But when it arrived I was shocked just how good it is. There are afew very minor marks but it's damn good condition and you'd think it was only a year old. It also has a higher spec that it was advertised with. I was expecting it to only have an onboard Intel HD4000 GPU, no blueteooth and the standard 6 cell battery. But it actually has the switchable Nvidia GPU, bluetooth, the extended 9 cell battery and a fingerprint reader. Result
It's ideal as I don't game much now and I can set this up as a work machine desktop replacement. It's powerful enough for it and with the Nvidia GPU, if I add the right Thinkpad dock, it can drive three external monitors as well as the onboard screen as a fourth monitor.
Quad core i7 3630QM
8gb RAM (I will upgrage that to 16gb)
320gg HDD (I will upgrade it to an SSD and relocate the old HDD into the ultrabay
DVDRW (not needed - would prefer the HDD in there)
1600x900 15" matte screen (I will upgrade it to 1920x1080 for about £60)
webcam
bluetooth
Fingerprint reader
Non-backlit keyboard (I won't bother upgrading that to backlit as the non-backit keyboards are more tactile and have a rough rather than smooth key surface which I prefer - and of course it has the Thinklight). The keyboard is not quite as good as the old style pre-chicklet Thinkpads but almost as good).
It's certainly no lightweight pretty little ultrabook. But it's not as heavy as I expected and is really quite powerful for a cheap five year old machine. Exactly what I was looking for.