I found this at Amuse Yourself! Blog:
"The Downing Street Memo Meme Song
(sung to the tune of 'Rawhide')
Downing, Downing, Downing
Scott McClellan's frowning
'Cause that Downing Memo won't hide
'Though Blair was re-elected
And Dubya re-selected
Neither liar's got time on his side
They think the truth can't reach 'em
But wait 'til we impeach 'em
Wait 'til they're indicted, cuffed, and tried
Blog it up, get it out
Pass it on, give a shout
This is real, there's no doubt
They lied!"
The rest is here.