You're right,and I recall Bowie in an old Radio 1 Rockumentary admitting that they were basically being 'Pete & Dud' during the production & mixing of 'Low'..."'ere Pete what about adding a bit of flange on the snare drum" etc etc.

Speaking of which, Word Massive should check out the Adam and Joe show on 6 Music/Iplayer or their brilliant Podcasts via Itunes.

They both do the most uncanny (affectionate) Bowie impersonation and occasionally slip into a fantasy scenario where Bowie is really keen to appear on their show but "er...oh I've got to do a couple of inz-dallations at the Whitechapel Gallery, and I'm mix-zing a new album with Baaba Maal, but I'd love to come on your show on zixx muzik..I'll bring some Drum & Baaszz recordz with me...wuzza wuzza"

… this kind of tribute by producers to comedy performers has a long and distinguished history. The Beatles were often to be found helpless with laughter at the antics of George Martin as he ran through his Arthur Askey routine, while Biddu's reworkings of Mike & Bernie Winters material with Tina Charles helped the creative juices to flow.

More recently, Mark Ronson has built a huge reputation as Bobby Ball to Daniel Merriweather's Tommy Cannon ("I piggin' hate you, Tommy").

... with Monty Python sketches? Or am I imagining I read this somewhere?

Both Tool and Radiohead dedicated albums to Bill Hicks as well. And I'm awfully partial to "Lenny Bruce" by the Boo Radleys