Best use is probably Flight Gem in conjunction with Acrobatics, as many people have already stated. I'd like to present another user, though, in Archeops. Even though it's RU, I've been getting steadily good results with it in Wifi OU. Here's my set (unintentionally cribbed from the official page):
Archeops @ Flight Gem
EVs: 4 SpA/252 Atk/252Spe
- Stone Edge
- Hidden Power: Ice
The set gets good neutral coverage of most OU 'mons, and can deal ridiculous damage with the first Acrobatics thanks to the Flight Gem. HP Ice is to mess up Dragons and Gliscor, as well as snag some extra damage on Landorus. Pretty much, avoid their priority and Scarfers and you can do some serious damage. Not as famous as Gliscor, obviously, but it's still a legitimate use of one of the Gems in competitive Pokemon.