I'm looking for something to do MOSTLY WORK on with a little minecraft on the side 
Needs to be around 2GHz processor, I don't mind whether AMD or Intel, dual core is all I need. Maybe less than 2, 1.8 maybe?
At least 2GB RAM
Relatively light as I will be carrying it around a lot
Cheap (Max £250)
And most importantly, must work FLAWLESSLY with Ubuntu.
Any suggestions?
Edit: 2GHz is quite a lot for a laptop, I could go much lower.

Needs to be around 2GHz processor, I don't mind whether AMD or Intel, dual core is all I need. Maybe less than 2, 1.8 maybe?
At least 2GB RAM
Relatively light as I will be carrying it around a lot
Cheap (Max £250)
And most importantly, must work FLAWLESSLY with Ubuntu.
Any suggestions?
Edit: 2GHz is quite a lot for a laptop, I could go much lower.