Set yourself a challenge and invite your friends, family and colleagues to sponsor you! You can ask your friends and family to sponsor you online via Localgiving.com or Justgiving.com.
If running is your thing, there are lots of local and national runs you could tackle.
You could try:
London Landmarks Half Marathon
Cancer Research UK London Winter Run
The Kingston Rotary Dragon Boat Challenge is always great fun and you could be competing against our very own young carers.
If you are up for something more adventurous then take a look at Skyline Events where you will find opportunities to skydive, cycle to Paris and even trek the Sahara!