Ask HN: Should I accept an unpaid internship?

I recently finished my freshman year of college (quarter system = late start/end). I have an opportunity to work unpaid for a medium-sized IT company, Coradiant Inc., in the Bay area. They are willing to cover travel costs and I can make arrangements with minimal living expenses. However, this would require postponing projects I had planned to start this summer (not all of them programs - I'm eager to start learning quantum mech, for example), and having no income doesn't help with student loans.

My assessment so far is that the internship is more resume-friendly and will probably bring positive recommendations later, but an independent project summer will allow me to learn things that are more important/useful to me.

How valuable are internship experiences to entrepreneurs, compared to executing your own projects? Are there any other factors that should weigh into this decision?