How about working at a bookstore? Also, I don't know about your town, but our parks & rec has children's programs in the summer and they pay very well for responsible teenagers to work with the kids, plan activities, etc. A daycare center might also want help, though I'd imagine they'd want you to be at least 16.
Oh yeah! If you are good at crafts and such, and you have a local market, you could make lots of goods and sell them there. My friend made hemp necklaces and wire earrings, and she did quite well for awhile. My aunt actually makes gorgeous jewelry as a hobby and sells them simply by word of mouth...
I also had my own hobby/business last summer, though it took me a long time to get to the skill level that people would be willing to pay for and I didn't make a lot of profit after all the time, energy and money I put into it... it was still worth it though.
There are all sorts of jobs that you could do... although I guess it does depend on where you live. I'm really close to a decent-sized city, so there are lots of job opportunities here. Most of them do involve retail, but there are many other options...
-sports team mascot/fan (seriously, I know someone who was hired to do this)
-newspaper carrier (even kids can do this in our city)
-door person at local pool/ theatre
-movie theatre person (sell tickets, sweep, etc.)
I'll think of more later if I can