Fundraising help/ideas

Hi IM's!
Got a non parenting question (or rather need ideas)...
In April my two sons (ages 6 and 9) plus myself are doing a 5km fun run to raise money for Alzheimer's Australia (my grand mother suffers from dementia). I want my boys to do this fun run to learn that life is not all about taking and to teach them the joy of giving back to the community. The only problem is I'm stuck for ways to help them get sponsors and raise money. I've set up a donation page online and also put the word out on Facebook so I'm just after some other ideas to help get donations. Have any other IM's fund raised before and what worked well?
TIA :)