I thought this was cool when I saw it:

The iDea Ovation - guitar with recording studio built-in

From the site:

iDea OPI-1

The groundbreaking iDea OPI-1 preamp provides a fast and easy way to record musical phrases, vocals, and voice memos—even entire songs—using your guitar.
Using the OPI-1’s MP3 capability, you can:

RECORD Capture guitar and vocals simultaneously using the system’s saddle pickup and built-in microphone. Store over 100 minutes of MP3 files.
PLAYBACK Listen to recorded or imported audio through headphones or guitar amp. Change playback tempo without changing pitch.
CREATE Quickly record song ideas, licks, hooks, and rhythms. And with the OPI-1’s USB connectivity, you can upload your ideas to your computer, and then use recording software to edit and expand your creations.
LEARN Download lessons and backing tracks. Record songs or solos from MP3 sources, slow them down, and learn them note-for-note. Equipped with an OPI-1, your guitar becomes a creative partner.