Just got an email from Red Octane saying they're having a 1 day sale on the Guitar Hero III wired X-Plorer bundle for 360. On Wednesday 10/28/08 between 6am to 6pm PST, it'll be $39.99.
Looks like it includes a free guitar carrying case and GH keychain too. Pretty good deal for anyone that doesn't already own the game:
http://www.redoctane.com/Guitar-Hero...?leadsource=28