Activision has registered the trademark "Guitar Hero On Tour" in the US, but the publisher's British representatives had no comment to make on that this morning.
Inevitably there is speculation that this could be the name of the DS version of Guitar Hero mooted last year.
It's certainly not the name of anything on Activision's release schedule, and the publisher is another of those spoilsports that refuses to comment on rumours or speculation.
Developer Vicarious Visions has previously hinted at an actual peripheral to go with the DS game, although we somehow doubt it will be an enormous PS3/360-style guitar that you plug in to the cartridge port or anything.
We asked Activision for more details on the DS version of Guitar Hero and they told us to go away, which is fair enough because it was two in the morning and how did we get their home address.