OK EVERYBODY, relax. It's all over. James Boyle has retired to the Highlands to refine his knowledge of plumbing; John Humphrys is to become Chief Druid in Perpetuity, and Jill Archer has seduced Joe Grundy and discovered a cure for farmer's lung. The Home Service is to be reintroduced.

Well, we can dream. Especially if April Fools' Day coincides with the dying gasps of the old Radio 4. Mind you, when newspapers announce that a woman had consensual sex with Bill Clinton, it's not easy to establish who's fooling whom. Still, here are a few radio April jokes. I think.

A perfect prank is always plausible. Midweek (R4), forever the last refuge of the terminally weird, produced a man who would introduce a happy gas into the Millennium Dome. It will render all visitors blithe and blissful and, like fluoride, it will be beneficial and undetectable. If we insist on staying grumpy, gas-masks will be available at the door. He sprayed some of the stuff noisily around the already giggling studio. Only Libby Purves, at her most head-girly, claimed to be unaffected.

Kevin Greening and Zoe Ball (R1) staged a savage row, ending with Zoe sobbing and storming out, while on Talk Radio's Breakfast Programme Kirsty Young announced that a Hollywood film is to be made of the Teletubbies (Christopher Biggins was earnest about the challenge of his role: "I think I can bring a lot to La La ... this could be my big break"). On Breakfast with Bailey (CFM), however, the joke was on Nick Bailey, who innocently read out a traffic report about a bus service between Portsmouth and Ryde (yes, it's on the Isle of Wight).

Apart from the last, these merry japes are all too believable - but I've got a horrible feeling that the repellent "Snoozipaws" dog-warmer described to Debbie Thrower (R2) really exists. And I want to believe the woman on Start the Week (R4) who said that the notion of the one-eyed giant Cyclops springs from the remains of mini- elephants in Crete.

Enough frippery. With inverted serendipity, Reggie Kray's request for parole was refused just as a play reminded us of the scary days when the Krays were free. Frankie Mitchell was a huge, violent, unpredictable murderer, son of a cattle-slaughterer. His father had told him that when a cow is killed it gives one last twitch before it dies, a Jump to Cow Heaven (R4). His own last twitch happened when the Kray twins sprang him from Dartmoor and he spent two weeks in an east London house - before disappearing forever.

Reggie Kray now longs to settle in East Anglia. In Gill Adams's play, Frankie (David Troughton) has similar dreams of a rural paradise where he can lead a normal life. But this "mad axe-man" isn't going to survive. His minder, John (Andrew Tiernan), tries to placate him, ridiculously, with Battenberg cake. But Mitchell demands a woman. When Lisa (Anita Dobson) arrives, a strangely tender, unlikely romance develops between them.

The play celebrates the heartening possibility that some kind of love, however frail and imperfect, might flower in the thinnest, poorest soil. It was directed with tangible, hand-wringing tension by Kate Rowland.

Now, we're off into the virtual world of electronic know-how, beginning with Jon Ronson's investigation of the credit card, Flexible Friend or Foe (R4). Ronson sounds like a timid poet or a newly-ordained deacon, but he's stilleto-sharp. He found a girl who was once the Imelda Marcos of bed-linen, building up colossal debts - that is, until a salesgirl phoned Barclaycard and was instructed to "cut up the card in front of Madame".

The astonishingly plummy inventor of plastic money has clearly retired on the profits. He's happy now and has "washed it all out of me hair" - I could swear I heard the slurp and clink of his decanter. Ronson then interviewed the head of Visa UK, a man nervous of speaking without his PA's permission: "Do we say that, Camilla?" he kept asking. In Florida, a beach-bum called Lin has a collection of 10,000 of the things. Heaven knows why but it makes the languid Lin happy.

The most stimulating listening of the whole week was Michael Kustow's Dionysius and the Mighty Mouse (R3). Homer called the orderly Apollo the Mouse God: did he guess at the existence of a computer mouse, summoning everything tidily on a screen, to be viewed by an isolated individual? In the endless opposition between these extremes, Kustow is for Dionysius in all his dynamic intoxication, as representing sociable activity, live theatre, the real thing. He saved his greatest scorn for a wedding held in a cyber cafe, where the parties were in different countries and the bride celebrated by kissing the screen ...

Which leads us to Silicon Sex of a Virtual Nature (R4): unsatisfactory, as you might imagine. This was a short, late play about an unlikely e- mail affair between M Bankment and Millie Narium and that was the best joke. There was a whole wasteland full of random references, mixing uneasy memory with a sleepy desire for repose. What a cruel month April is.