I coundn't imagine not having worked in high school. I started working at 16 and worked up to 25 hours a week during school, while keeping up with all my extra curriculars (band, orchestra, plays) and graduating with a 3.9. I just couldn't imagine having my parents pay for everything anymore. I wouldn't be able to get the clothes I wanted, or take vacations like I do now. I left for college with over $2000 in the bank, besides what I paid my parents for car insurance and what I had spend on clothes/activities in high school.
I actually found it harder to work in college than high school, just because my class schedule is so varied. I do some work for my dad's company online, but also found a job babysitting around 10 hours a week. I worked at Abercrombie in the fall, but spent more than I earned, so I decided it wasn't worth it. So I quit, but purchased $700 in gift cards before I quit at the employee rate of 30% off. Thus, prepaid for clothes for a fairly long time.
I know some kids aren't able to work during high school because of sports, but I don't see what they could be doing during the summer that's so productive that they couldn't work a few hours a week. It was honestly just really nice having my own money, and I'll appreciate it when I graduate college and have money in the bank.
On one extreme, a friend of mine graduated HS with a 4.0, and earned almost $50,000 a year owning her own petsitting business with her older brother. She went to college driving a year old Mercedes convertible, and later sold it for a profit, and now has over $100,000 in the bank that she's going to work on investing this summer while she interns at Lehman Brothers in NYC.
ETA: forgot about trips - I paid for my own way to Disney senior year as a senior trip with my boyfriend. Since then, we've also gone to Hawaii and California, paying our own way. I never would have been able to do that without working - I think my parents would have laughed if I asked them for $1,000 for a spring break trip to Hawaii.