I reckon we pull a group effort and try to identify them all: post here and I'll update the list! Please state the name of the band and how you figured it out.
Here are some I've already found, don't look at mine if you wanna have a go yourself
Iron Maiden (statue of the lady in the middle)
Matchbox 20 ('20' made out of matchboxes)
B52's (two bombers flying overhead)
Led Zeppelin (the lead blimp)
Scissor Sisters (the two pairs of pink dancing scissors)
Smashing Pumpkins (this one's a no brainer)
The Eagles (duh)
Red Hot Chili Peppers (the peppers on the veggie stall)
Blur (the blurred man)
The Rolling Stones (duh)
Spoon (duh)
The Beach Boys (the two surfers)
The Eels (the two eels)
Pet Shop Boys (two kids by the pet shop)
50 Cent (the giant 50c piece)
Boney M (the 'M' made out of bones near the matchboxes)
Cake (the cake on the bottom left)
Guns 'n Roses (the shotguns in the roses)
Alice in Chains (Alice in Wonderland chained up near Blur man)
The Gorillaz (duh)
Green Day (the green day highlighted on the calendar)
U2 (the two U's painted on the wall)
Lemonheads (the lemons with faces)
Blind Melon (the melon with dark glasses)
Korn (duh)
Currently 50 left!
Beware, the image is fairly large, weighing in at just under 800k:
EDIT: Just saw these ones...
Lemonheads (the lemons with faces)
Blind Melon (the melon with dark glasses)
Korn (duh)