Someone in work pointed me to Freetar Hero - a free PC-based replacement for Guitar Hero. Nothing really new there, there's been a few out there already. But what sets this apart is the awesome new Freetar Editor, which allows you to create your own levels from your MP3 collection.
As this video demonstrates, the upshot of this is that I might actually get a chance to rock out on my Guitar Hero to Journey!
Looks like Mackers won't have to buy a TV to play this after all.