Yeah, Yeah, Yeah, Yeah; I fancy driving a ferrari around the world for the next few weeks, how the hell am I gonna afford that? Oh yeah! I'll just say it's for a worthy cause, you know, some big charity and hey presto I got my (few thousand) sponsors.
Give me a break! If you really want to do something charitable, volunteer to work at the local hospice on a regular basis. Empty and clean a few bed pans, clean up some vomit off the floor, wipe a couple of bums. THEN I'll have respect for you.