Just been to my local Tesco Extra this evening and picked up 2 small, thin light laptop bags for £1.50 each. (upto 15 inch screen at a guess)
The bags where at the end of an isle in the £1.00 section,, (red boxes, cant remember what is says on them.)
Anyway.. the laptop bags are plain black and thin and look ok.. (no real support as there not hard back)
For me.. these bags are ideal for site visits where i don't want to be carting around my large heavy laptop bags for us of my tablet laptop.
For the price its worth it if you need something like this..
I will post barcode if require..