A Macworld article indicates there are currently over 500 guitar-related iPhone apps.
Every up-to-speed tech geek, guitar player will want this mechanical interface.
You’re looking at the Guitar Sidekick, an accessory for mounting your iPhone, Blackberry, Droid or other similar media devices to your guitar. The above article link tells you all about it, but the picture basically says it all.
The Guitar Sidekick is available at: www.castiv.com
(Via Strat-O-Blogster Guitar Blog.)