Patrick Barlow and Jim Broadbent were the original National Theatre of Brent, with an approach to the great themes of drama somewhat akin to that of the painter LS Lowry's to the industrial north: apparently naive but actually perceptive. Barlow and Broadbent, on their own, tackling everything from the nativity to Shakespeare, were very funny. This is Barlow's take on the story of St Joan, maiden warrior and martyr, played here by Dawn French. Broadbent appears in the unexpectedly large cast list which includes Cheryl Campbell and John Ramm, with Anne Reid and Maggie Steed as Joan's guardian angels.

New comedy by Nigel Williams, starring Jonathan Pryce and Nicholas Le Prevost, about an idle employee and his equally useless Human Resources officer. When they realise they're both up for the chop they embark on adventures which will occupy this space for the next six weeks. With a subject like HR, bane of the politically incorrect, and a cast like this, you can't really go wrong. Unless the script is clogged, self-conscious and leaves no room for the listener to enter the intense verbosity of the scene. As, alas, is the case today.

Cavity was glitteringly original. Sean Grundy's play was a comedy about adultery, fast, sexy and I'd have said 'edgy' too, if that word hadn't recently been bled of meaning. Here, I intend it to convey going as close as possible to the borders of descriptive propriety while employing sharp wit to induce a slightly shocked delight. Alison Crawford directed a marvellous cast - Julian Rhind-Tutt, Ingrid Oliver and Kerry Godliman - with glorious assurance. Afternoon Play is not often as utterly entertaining as this. Everyone, me included, usually moans about it. Frequently, these days, we must admit we can be wrong. If you missed Cavity, you missed a treat.

Sharp, sexy, surreal yet somehow utterly believable comedy by Sean Grundy. Adrian (Julian Rhind-Tutt) starts an office romance with Kirsty (Ingrid Oliver). He takes her home, thinking his wife, Lucy (Kerry Godliman), is away. But she comes back unexpectedly. Kirsty hides, falls into the cavity wall. One thing leads to another, and she stays. And stays. This brilliantly observed piece is not for those who shy at on-air sex. But for anyone who relishes characters who come to life in a situation which grows around them almost magically, don't miss it.

This is a first-rate sketch show lampooning the mysteries of modern communication. I discovered this last by accident and recommend it heartily. The standard of both material and performance is high and the production (by Ed Morrish) is pin sharp. The only hazard of listening (but a nice one) is that it goes out just before Today in Parliament and so makes that sound unexpectedly hilarious.

Also welcome in the prime 6.30pm slot is Broken Arts. It wasn't as consistently funny as Recorded for Training Purposes but I bet it will be, given a week or so. Even so, there were some moments of utter comic wonder, as in the DVD review of a classic (fictional) Doctor Who episode from 1974, The Catalogues of Argos, and an item on whether there should be Harold Pinter stamps (long ones, said one woman, to allow for the pause, as in Twenty... Nine pence). Best of all was the perfectly realised sketch where Gilbert and Sullivan come back to comment on such contemporary obsessions as football and talent shows.

Ah, the iPlayer. People who don't have computers are driven mad by its very mention. But so, according to Recorded for Training Purposes, a brilliant radio comedy series on Radio 4 late on Thursday nights, are many others. It's like saying "your programme's in the oven," they said, and why, when you can record TV and there are so many repeats anyway, was there all this iPlayer stuff all the time, "What do you want, an alarm call or something?" They also made fun of phone-ins, fatuous surveys which get onto the news, the ridiculous search for mad metaphors to popularise broadcast science. I knew I liked this show when they started with this week's National Sudoku Numbers. It's bold to make fun of the BBC when you're on it, but very welcome.

Comedian Phil Cornwell leads a different fictional life each week in his new comedy series. Every one, however, draws on his real-life experiences of growing up on a tough London housing estate. For openers, here he is as Dave Kafka who's just come out of jail and moved in with his grandad. Dave fancies himself as a bit of a lad. The thing is, he's nothing of the kind compared to Grandad, who really is a hard case. A very good cast, good production and sharp script make it sound both real and surreal. Listen via a computer to see it, too.

Comedian Will Smith (not to be confused with the American rapper and film star) has co-written this new sitcom in which he stars as himself. Reaching the age of 35 has depressed him at how little he has achieved. After all, he says, Christ had died and risen again by the age of 33, an observation which gives you a notion of the size of Will's fragile ego. So he draws in to this scenario his fictional godfather Peter (played by superb Roger Allam) who each week will invite a special guest to advise him on some perplexing aspect of his life.

Doug Lucie's play is sharp as a tack. Mike (Mark Bazeley) is a property developer. His wife (Samantha Spiro) presides over their slackly affluent household in which the son lies on the sofa all day (smoking dope, watching porn) and the daughter plans naff weddings. Their Russian au pair Tatiana (Larissa Kouznetsova) seems caught, powerless, in the midst of their multiple demands. But when the property market starts to tremble and topple, it's Tatiana who may hold the key to helping solve their problems. She has this brother, with useful connections.