Spotting fake autographs

Though it may not qualify as "literary fraud," the faking of sports autographs certainly has crossover elements. It's epidemic. Here's a good starter "how to" from the BBC: 

http://news.bbc.co.uk/2/hi/uk_news/magazine/7291412.stm

Just noticed a novel suggestion for those who want to avoid autograph fakery. Collect signed, cashed checks. I can see where there'd be risks but the odds favoring authenticity seem better than with other materials...