[highlife]

If this guy is just "An acquaintance from High School", why did he come to you? I mean, how does he know you have what it takes to make his business a success?

I'm not trying to imply that you don't have some very desirable skills, but just to explore why he picked you. How much did he really know about your capabilities and past successes? If he is just picking you because you are the only experienced programmer he knows personally, then you might want to consider his aptitude to run a business like this, and thus its not worth your time.