ThinkGeek offers the Bag 'O Rock 17" Notebook Messenger Bag
in Black for $49.99. Coupon code "ROCKON15" knocks it to $34.99
. With $6.49
for shipping, that's $15 off and the lowest total price we could find for such a bag. This canvas bag features a playable "guitar" (major chords only), clip-on mini amplifier which really goes to 11, magnetic flap closure, adjustable shoulder strap, two interior pockets, interior space for up to a 17" notebook, and more. It operates on four AAA batteries (not included).