So far my main methods of raising funds have been:

eBay
I have been selling various items found around the house that I no longer want or need. These have been mostly old toys, including Pokemon cards and a badge maker, but I have also sold numerous back issues of Kerrang! Magazine, some DVDs and a mini fridge.
New items will be added regularly, so please feel free to have a look and see if there's anything you want!

Saving money
I have been putting a little change into a pot each day which is very slowly adding up. I have also saved birthday money.

Working
I am currently working in a pub. All of my wages will be going into my Africa fund (minus tax, as I won't be able to claim that back before I leave). I'll hopefully be able to raise at least half of the required funds this way. =)

Future endeavours
I will also be taking plenty of stuff to a car boot sale in the near future. In addition I hope to try and sell some of my better photographs (more news about that later), and am planning to hold a fundraising event at some point too.