I've been mulling over purchasing a secondary screen for quite some time now and spotted the Iiyama Pro Lite B2409HDS 24" for £159.99 on Play.com for this weekend only.
I just placed an order and thought I'd make a thread about it incase anyone else is interested
I'll maybe look into some methods which are good for testing monitors. Might even buy a calibrator while I am at it, and show the difference before and after calibration.