Many years ago my DH taught at a community college that participated in a program called "Running Start." The best and brightest kids at the local high schools could do some or all of their junior and senior years at the CC instead. Many were awarded an Associates degree along with their high school diploma.
As pointed out by the PP you have to be careful about transferring the credits though. This CC was a "feeder institution" to a particular regional university in the state system. Students who chose to continue somewhere else did not necessarily have all credits transfer. Since the CC was on a quarter system many schools on a semester system were unable to transfer the credits in any sort of meaningful way. (i.e. the courses were calculated to be short a few hours so the student would receive 3.72 credits but needed 4 for the class to count.)
It was a great program for the students who participated, many of whom had spent years being bored and unchallenged. The biggest drawback I saw was at the local high schools. When you pull out the best and brightest what does that leave behind? Smart kids who were either not quite at the level to do this program or whose parents didn't support it were left in an even less challenging environment. It did however make attending college affordable for a whole lot of smart, economically challenged kids who otherwise may have never found a way to attend.
