Like everyone, I want to do my bit for reducing my CO footprint.

I live in the UK, so theres not that much sun here Should I buy a portable solar charger? something I can face out from my bedroom window to pick up light.

If so which is the best product to go for?

If you do most of your charging at home then you would be better to get your supply from a 100% renewable energy supplier;

http://www.good-energy.co.uk/

Centralised generation is more efficient than micro generation, which is one reason why the government are cutting the micro generation grants. PV panels are not the cleanest form of renewable energy anyway.

solar chargers can be found here

http://www.good-energy.co.uk/

Go for the portable charger! When described as portable they really can be. OK, in the UK we don't have much sunshine at this time of the year, but it will charge but take longer. Have a look in your local outdoor gear suppliers. I got one from Field and Trek.