To participate? It's linked from here:

http://www.get-fast.net/nasacross

Or the 4/22 event info & pre-reg page specifically is here:

http://www.nasaproracing.com/nasa_ev.../?event_id=491

7 spots left as of this moment: 4 in heat 1, 2 in heat 2, and 1 in heat 4.

Thanks,

Jon