The Worth 1000 web site has daily contests for people to Photoshop pictures for various themes. Right now, they are having their second Chop-a-Uke theme, in which people are creating photos that include ukuleles.
http://www.worth1000.com/contests/30368/chop-a-ukulele-2
http://www.worth1000.com/contests/30368/chop-a-ukulele-2