I've just found the best article
I've ever read on how to get tickets to the Wimbledon Championships. It includes the crucial reminder:
"If you are caught trying to sell them on Ebay, they will void the ticket. Likewise, if you buy a Ballot ticket on Ebay, there is a danger that this will be voided."
It's true - this once happened to my cousin and it, along with some fearsome letters on official letterhead from the British mandarins at the All England Club, put him off Wimbledon tickets for five years.
The original article is clearly a plug for the author's website, www.wimbledondebentureholders.com, which seems to provide the only legitimate option for purchasing Wimbledon tickets directly from the Debenture Holders themselves. Wimbledon being a jewel in the crown of the English establishment, it allows "the right sort" of Brits to become Debenture Holders, which is like being a member of an exclusive club. These people are the only ticket holders who are actually allowed to sell their tickets online - and www.WimbledonDebentureHolders.com seems to be the formal association of Holders which allows them to sell tickets directly to the public. So if you buy from them, you won't be getting any of those scary letters or having your tickets voided.
But if you just can't beg borrow or steal a ticket, and your TV channels reckon that the game you really want to watch is too unimportant to screen, you might want to investigate the websites that specialize in screening tennis events: http://www.watchlivetennis.org/ or http://www.tennistv.com/page/Home/0,,11444,00.html. Anyone got any experience, or recommendations, of these?