An It's A Knockout is an excellent way to raise money for a charity or cause whilst giving the participants a fun time in the process.  We have had many charities raise money for their cause and below is a table of some typical ways of doing this:

If all the team members were given sponsorship forms they could raise money by approaching friends etc. This could be used as the entrance money.

We can also give extra points to the teams according to how much they've raised. So the more money they raise, the more points they start with. This usually entices the teams to raise more than the entry amount.