Were you in the Windows 7 Technical Beta Program? No, not giant public beta and release candidate tests, but rather the closed, invite-only technical beta that preceded it. If you were, good news - you're getting a free copy of Windows 7 Ultimate.
Brandon LeBlanc writes on the Windows 7 Team Blog:
"To show our appreciation, members of the invitation-only Windows 7 Technical Beta Program will be eligible for a free, final copy of Windows 7 Ultimate. For more information on how to take advantage of this, refer to Paul's post in the .Beta_Program newsgroup for details."
Basically, those who participated in the invite-only Technical Beta (if you did, you'd know it) will be able to download a copy of Windows 7 Ultimate and a key starting on August 6th, depending on the language you want. There will also be a limited number of boxed copies available after October 22nd on a first-come, first-serve basis.