I remember Lee and Herring doing these. always good for lolz.
We once came up with:
"Easton West": Sheena Easton and Fred West in a musical variety yarn.
"Saeed by Saeed": Cricketer Saeed Anwar and long distance runner Saeed Uhita (sp?) comment on each other's careers
"Houston Saro Wiwa Have a Problem": Whitney Houston and the ghost of executed Nigerian Ogoni Rights Campaigner Ken Saro Wiwa star in a Challenge Anneka-esque vehicle.