That Mitchell and Webb Sound, Radio 4<br/>The Call, Radio 4

If Anna Kournikova did comedy ...

Peep Show? Brilliant. David Mitchell on any of the roughly 795 radio and TV panel games he's adorned with his presence? National treasure-in-waiting. But if his reputation rested on his TV sketch shows with Robert Webb, the two of them might well be known as the Anna Kournikovas of comedy: famous, but useless at the thing they're famous for.

The problem with the sketches in That Mitchell and Webb Sound (which the lads mostly write), as opposed to Peep Show (which they mostly don't) is that they're clever but not very funny, a slight handicap for a comedy programme. Each situation is replete with comic possibilities and progresses with savage twists of absurdity. It should be drop-dead hilarious. It's the kind of thing, though, you watch with an expectant grin – but no belly laughs.

So I listened to the new series of the radio version with some trepidation, but although not everything was a palpable hit, there was enough to be going on with. Some of the ideas were spot-on, such as the orthopaedic suppliers with an inter-dimensional portal on the shop floor ("gentlemen, the stargate is not a bin"), or the iReckon, Apple's new gadget ("I can download all my thoughts from the internet!"). And Caesar being coached in referring to himself in the third person was pure Two Ronnies.

The week's funniest programme was The Call, a series about life-changing phone conversations. Monday's came from the home of the National Lottery, and heard from the people who take the tremulous calls. One of them told of a winner in her eighties who was a bit overcome and suffering a coughing fit. The exchange went like this.

"Have you got a drink of water?"

"I'll be all right in a minute – I'm just having a cigarette."

"It's all right, you take your time."

"I'm OK – it's just that I've never smoked before in my life."