Following are some websites you may find useful:

South West Thames Institute for Renal Research
Helier Scientific Ltd
Justgiving (online fundraising)
Virgin Money Giving (online fundraising)
BMyCharity (online fundraising)
Give a Car (recycle your old car)
Give As you Live (shop and raise funds for us)
ebay For Charity (sell an item on ebay and donate a portion of your profit)