The cue sheet for the Warrenton 300K ACP brevet starting at the Hampton Inn in Warrenton, VA at 5:00AM on May 2, 2009 is now posted at Cue Sheet - 20090502 Warrenton ACP 300K Brevet. GPS files are posted at GPS Files - 20090502 Warrenton ACP 300K Brevet.
Always get a copy of the final cue sheet. That final cue sheet contains the official route, so in case there is a conflict with the GPS file, you should resolve the conflict in favor of the cue sheet. Use the GPS as a handy-dandy adjunct. Keep your wits about you, as the GPS cannot notify you of road hazards — it is up to you to ride safely.
By the way … make sure that your GPS either has maps already downloaded, or select the relevant maps around the routes.