Alcorn was an 8:54 guy in HS. You might know him from winning the NCAA Indoor 3k a few weeks back, and recently breaking 4:00 in the mile.
Tim Nelson was an 8:53 guy in HS, who is also a ~13:45 and ~28:00 runner as of last year. Not sure what he is doing now, but he was on the Wisconsin XC Championship team in 2005 and was their #2 guy in 2006.
Mohammed Trafeh was 2nd at Footlocker XC and ran 29:54 for 10k in High school. Ran for Arizona for a couple of years and didn't improve much, but he was pretty close to the top of the heap while he was in HS.