It's been awhile, but nice to have you back, summer league basketball.
ClipperBlog has the complete 2010 Las Vegas Summer League schedule. The league runs from July 9th-18th. The Hawks play on the 12th, 14th, 15th, 17th, and 18th.
Plane tickets from Atlanta to Vegas appear to be running in excess of $300 right now. Budget accordingly but remember, jumping to conclusions is priceless.