What are good summer internships for high-school students in New York?

You're in high school. Any internship you take, especially in New York—by the virtue of you being a junior in high school—will either be so pointless as to not justify the expenses related to it or else so amazing, so fantastic, that you would have to be rich enough for your parents to buy you the position. Take a job at your local grocery store. You'll have money, a space to develop a work ethic, and you won't turn into another guy who's never worked a real job before. You're, what, 17? Pay your dues. It will give you so so so much perspective. Then the job you take as a 24 year old after you've backpacked in Europe after graduating from Bowdoin will mean something. Learn how this half of life works, and in time, you will learn have a life, an occupation, and a place to call your own.

I hate to break this to you, but often times college juniors can't even get summer internships in New York. I'll echo fearnothing: volunteer at a non-profit.

I disagree with Trotter. You can get an internship, and paid at that, at your age, and have it be very meaningful. My non-profit arranges this with its member/sponsor companies each summer. Last summer, we placed about 75 high school students all over our state in construction (job sites, offices, etc. all with OSHA 10-hour training). We have a pretty unique situation, but there's another program you should look into. Check out ACE Mentor. Go to acementor.org to learn more. It's geared toward high school students who are interested in architecture, construction or engineering, but you don't have to be committed to any of these fields as a career to join. People interested in the trades are especially encouraged. Look at it as a no-obligation way to research a career in the second largest industry in the US (only healthcare is bigger), gain a mentor and possibly even get paid and get a scholarship at the same time. ACE Mentor started in New York and it's one of the biggest programs in the nation. Good luck!

Given your interests, you might want to see if any of the public/community radio stations need volunteers. I volunteered with my community radio station when I was in high school, and it was great fun. Lots of interesting people, and I'd imagine there's a decent amount of tech stuff, too, though I tried to stay away from that part. I mostly worked in the news department writing local stories, but if there's a music show you like, it couldn't hurt to ask if there's anything you can to help out with that particular program.

Thanks for all of your comments—I've begun contacting New York organizations I'm interacted with in the past, but I'm also intrigued by the possibilities of public-radio or nonprofit service. http://ask.metafilter.com/112779/What-are-good-summer-internships-for-highschol-students-in-New-York#1621089: I take your point, and I'm aware of the perils of becoming, as you say, "another guy who's never worked a real job before." Here's the catch: If I wind up taking an internship this summer, it'll be because I've been turned down (a significant likelihood) by a seminar program. My chief interest either way is in the work itself, be it academic study or office chores, but I'm trying to plan contingencies with similar résumé-value—hence the search for an internship. There are many different forms of contingency, of course, and my fallback—advertising my computer services within my community—is only slightly less of a "real job" than what you suggest. Alas, the résumé game is one I have to play.