Didn't see one earlier (though my awesome searching skills leave much to be desired) so I'll add these I found through the link on a webcomic, for a One Piece/DBZ crossover thing at an anime convention on multiple screens - pretty cool, actually. Ener versus Goku and Luffy!
First (bottom two screens):
http://www.youtube.com/watch?v=2rH_Z...ention%20anime
Second (top screen):
http://www.youtube.com/watch?v=h5f0k...ention%20anime
EDIT: Thank you mods.