If you're interested in the Time Trial event and haven't registered yet you can do so up to 5pm Saturday 6/26 at Chainwheel. I don't believe you can register on-line any longer.
Also you have to have a USAC license to participate. Like USAT, you can purchase a one-day license if you don't want to spend the $60 for an annual membership. I believe the one-day license is $10 and can be purchased at Chainwheel while you register.