If anyone is interested in doing the National Half Marathon, the race website says it's on track to sell out by Friday.
More interestingly, though, there is a half marathon relay I'd love to do. It consists of two 5 mile legs and a 5K anchor leg. The team competition itself isn't particularly competitive, but we could race against the race leaders (65:03 won last year), or at least try to beat Dirk's time from last year (67:37). Presumably we would all need to enter the half marathon before it closes, so let me know soon if you're interested in fielding a team.