Also of note in the Best Buy sale this week... Naked Brothers for $9.99,
with Logitech microphone included.
That's a $25-30 microphone by itself, from what I've seen on Amazon/Newegg. Works with GH:WT, RB1, RB2, GH:M, and probably any other karaoke/voice game.
If you already had guitars and got game only, a sweet deal to pick up a mic. And FYI, Gamestop is currently giving $5 store credit for the game only. So I really got a $5 microphone, and put a reserve down for Tiger Woods.