How do you Authenticate signed memorabilia?

 Say you were at an UFC or a place that had a someone like Randy Couture or Oscar Delahoya there and got a pair of gloves signed.



Say you wanted to sell those gloves online.



How would you authenticate them so the buyer knows the signature is not fraudulant?

take a picture

 http://www.psacard.com/submission_center.chtml



http://www.spenceloa.com/



For something like a glove, you would just get a certificate card: