If he's just looking for the summer you should try seasonal things like yard work, etc.  Go check with the local golf course and see if they're hiring, or something along those lines.  Marinas and such are another good place.  Or you could even try DQ :)

I've never worked at a grocery store, but most of my friends did when they were around 16 years old.  They said it was the most horrible thing ever, and they were too young and stupid to realize they could just quit.

I worked at a Dairy Queen for a while, too long actually, and I thought it was great.  I actually made a TON of money while I worked there, and most of my best friends today I met there. 

Any fast food place or Target type store is an easy job for kids.  They're good about working around with the schedules for whatever the kids need to do, so the hours shouldn't be bad.

buss boy,

You don't need any experiance and you can train in as a server if you do it for awhile.

Absolutely!!  AND, if you're good, you'll make some cash!!