Digital recorders for your guitar playing are two a penny, but the Ovation iDea guitar apparently represents the first time digital recording has been built into the body of a guitar.
Inside the acoustic-electric instrument sits an MP3 player/recorder, tied into the pickups and with a separate musician-facing mic. It can record the guitar alone, guitar and microphone, or the source plugged into its aux socket--essentially letting you record your jamming sessions without requiring any extra equipment. The control panel even gives you basic control over the sound quality with a tiny equalizer, and it can play MP3s back to you so you can either accompany yourself or listen to a backing track.
Sounds like a great way to learn to play guitar, but it's not cheap: The iDea will cost you in the region of $600.