Made a few suttle changes:
http://biketrialsdave.pwp.blueyonder.co.uk/BlasterFinal.JPG
Better.
As a rule you should be using more ground stitching between top and bottom layer. Don't be shy to put extra vias, it doesn't really cost you anything.
The bypass caps are still too far away from the chips IMO. U1 and U2 for example have plenty of room to put the bypass caps right at the pins.
You should put the bypass caps right at the pins first before you route anything, and then work around them. Then only move them away if you have no other choice.
You seemed to have placed all the passive parts away from the chips in neat alignment and then routed *to* the chip. That technique can produce aesthetically pleasing placements, but it's not so good for signal integrity.
What is your routing width and grid?
Don't be afraid to go down to say 5 though track and spacing if you are having the board professionally manufactured, that will give you much greater routing density.
Other niceties, like C2 and C3 should really be at the back of the connector to prevent those unnecessary long traces going to them.
Apart from a few subtle placement things and the odd trace, I do like your layout, it looks quite neat, and you've followed good aesthetic design practices.
Dave.