We currently use Team Foundation Server to do our builds.  I know we can tell TFS to keep our builds for a certain amount of time or keep them indefinitely.  What if we want to keep some or all of our builds indefinitely in case we need to go back to them for some reason?  Do any of you use source control to store your builds or use some type of file server to keep your builds on a file server for future retrieval?  Storing the builds within the Team Build directory would cause that directory to get very messy quickly.Of course we can always branch out an old changeset and create a build definition for that branch, but that's more time consuming than retrieving a build from source control or from a file server.Maybe what we're trying to do is just a bad idea.
Where do you store your builds?
builds