Ok,

1. He's 17 and in HS, so his hours of availibility are pretty limited.
2. He's under 18, so the duties he can perform are pretty severely limited by laws -- can't lift much. can't work past like 10pm, can't operate nearly any equipment, can't server alcohol (lawyers and frivolous lawsuits suck)
3. Many places require cashiers to be 18, so alot of retail jobs are out.
4. Even alot of busboy type jobs require that you be 18 -- liability again.

That leaves most of the craptastic food service jobs, and a rare few telemarketing style jobs.