Actually you are doing it becuase you want to do the entire trip with your mates for a laugh without paying a single penny out of your pocket and you think the best way to do this is under the thin veil of a 'charity event'.
You want to go to Europe, but you want other people to pay for you. If you can make it look more acceptable by donating whatever is left after your holiday to charity, then hey...
Obviously I will take all of this back and issue a full apology if you are paying your own expenses and donating ALL the income to charity.
Anyway, I must go, I am planning my charity BMW purchase - I am getting people to sponsor me to buy a 530i - all the left over cash after I've bought the car will go to Cancer Research.... so im really good and do stuff for charity, nothing to do with the free car obviously...