In case you were wondering, 0.5K is equivalent to 546 yards, or roughly the length of 1.75 football fields. A really long slog.
Much like its longer counterparts, the "race" is a fundraiser, and will be benefitting Blessings in a Backpack, a non-profit that feeds in-need school children on the weekends. $25 gets you a spot in the "run," while those who don't feel like actually exerting any energy at all can secure VIP status by paying another $25 to abstain while receiving an even bigger medal (and the free beer, of course).
Unfortunately, if you live near Boerne and were hoping to get in on the action, the "race" is officially sold out. However, organizers are working to secure the proper insurance (and beer supply) to allow for an even bigger event next year. So... keep up the not-training and hope for the best!