Only ladies who are going to put on 28 lbs in a month through eating burgers, or read the whole collection of Sven Hassle books, or have a dead rat kept in their knicker drawer for a year, or try a sponsored "stay at a Hotel which doesn't have Molton Brown Products in the bathroom" need apply.
And as for the men , how about trying a sponsored "not leaving your underwear on the floor" month, or a "read every Mills and Boon publication" challenge, or 6 months of "always driving at 10 mph below the speed limit whilst wearing a hat and driving gloves", or a sponsored "buy your wife or girlfriend whatever she asks for without moaning to your mates" month, That I would happily pay to see. In fact that last one reminds me of the best sponsored event I remember. If either of the two participants involved failed with quite a daunting challenge, they had to make a large donation to the political party they most detested. And as the bet was between 2 Northern Irish fellows of opposite religious persuasion. It made for great competition.
Now if you are in agreement with me then I look forward to your suggestions so that I can add them to the Polemic List of Acceptable Challenges. If you don't agree then I ask you to make a contribution to the Polemic "Swanning about at home watching telly followed by a 2 week villa holiday in the south of France" sponsored challenge. All donations going directly to costs.