Go to the Cheats Menu and enter the following cheat codes.

D1G? - Unlock Daft Punk items
k07u - Unlock DJ AM
n1fz - Unlock DJ Jazzy Jeff
oMxV - Unlock DJ Shadow
5rTG - Unlock DJ Z-Trip mixes and character
Ami8 - Unlock Grandmaster Flash
uNA2 - All characters
LAuP - All decks
62Db - All headphones
82xI - All songs
Wv1u - All venues
tol0 - Unlock All Content