Possibly this is for CS, but I’ll start in GQ 'cos it should have a simple answer…
A friend seems to have noticed this catchphrase all over the blogosphere, sometimes with the second phrase tacked on:
“See what I did there? [Comedy genius!]”
Usually, it’s used in a wry, self-deprecating way to refer to one’s own flat puns or jokes, she says.
She wants to know if there’s a definitive origin for it? Possibly a stand up comic or a Brit-com? Can anyone enlighten us?
I first heard it some 4–5 years ago, used by popular BBC Radio 1 DJ Chris Moyles in exactly the context your friend describes. It may not be original to him, but it fits perfectly with his on-air persona as “The Saviour of Radio 1”.
I don’t recall hearing “Comedy genius” (though I haven’t listened to his show in some time), but that sounds like him (or his style) too.
I’m almost sure I saw something like this on an episode (or more!) of Family Guy, spoken by Stewie. I have no idea when that (those?) episode(s) occurred, so that might not help you!
Close, but in that movie Billy Crystal was mimicking several of the old Vaudeville comedians that were still working when he was a kid. George Burns used it in his movie * Going in Style (1979) *, but it was most famous with Milton Berle.