I recently attended an event about Give as you Live, whereby shopping online through the website via click through links, a percentage of what you buy is donated to a charity of your choosing and at no extra cost to you. Connected to all 220,000 UK charities, Give as you Live can be used with over 1,3000 retailers including the big ones like Amazon, Topshop, John Lewis, Boots, Debenhams, iTunes, House of Fraser and so on.
I now do the majority of my shopping online and I tend to buy almost everything from Amazon because they really do sell EVERYTHING! My chosen charity is PDSA and I've downloaded the app for my browser so I won't forget. I've raised about 30p from buying some kitchen items so far :)