The Ricky Gervais Show (C4), which is produced by HBO, is an animated version of the radio show and highly successful podcast by Gervais, Stephen Merchant and Karl Pilkington. The format involves Gervais and Merchant making fun of "the little round-headed buffoon", as Gervais calls Pilkington, whose homespun wisdom is a morose combination of the absurd and the mundane.

Gervais's cartoon looks like Fred Flintstone with a hint of Oliver Hardy, and the lack of resemblance makes you wonder why they didn't just film the three men. For one thing, it wouldn't have been any less funny. The strength of the audio show's comedy lay in its flights of fancy, with which the audience were at imaginative liberty to amuse themselves. But now the surreal jokes are pinned down, and therefore restricted, by cartoon illustrations.

The result looks like the kind of thing at which a student might laugh after holding in marijuana smoke for a long time. You'd have to get mighty stoned, though, to giggle and howl as much as Gervais. It used to be a great comic effect, that laugh, but it's beginning to get a little irritating, like the sound emitted by someone happily going all the way to the bank.

I've never really seen the point in Ricky Gervais's podcasts: him and his mates Stephen Merchant and Karl Pilkington rambling on about nothing in particular. Well, mainly Pilkington, who just gets hold of an idea and runs off with it, like a naughty puppy.

But I get this even less: it's just the same podcasts, animated. So you've got Ricky, Stephen and Karl, turned into what look like characters from the Flintstones, rambling on about nothing in particular. Occasionally one of Pilkington's wayward thoughts - babies being born to dying 78-year-old women, for example - is animated, too. That's very lazy TV, isn't it? Radio with pictures. Maybe they should animate The Today Programme. I'd like to see John Humphrys turned into a Flintstone.

I guess it only works if you're amused by Karl's idiotic thought-streams. Ricky and Stephen clearly are: they spend most of it giggling hysterics. It leaves me cold.

Have a laugh on Ricky Gervais

Gervais laughing is the sound of the largest, smuggest gas leak in history.

Such is Ricky Gervais's cultural currency in the US that they're even hungry for his podcasts. The Ricky Gervais Show is the audio from Gervais's popular chats with fellow writer/director Stephen Merchant and their oddball former co-worker Karl Pilkington, fleshed out in cartoon form. If it sounds slender, be advised the material is strangely absorbing: with Gervais and Merchant set up to goad and mock him, Pilkington is given free rein to mumble his thoughts on topics from travel to newspapers, a kind of inspired rubbish.

Ricky Gervais, his co-writer Stephen Merchant and hapless producer Karl Pilkington have reunited to make these HBO-produced animated versions of their popular podcasts. It largely centres upon inane chatter with Gervais and Merchant encouraging naïve Pilkington to offer up his absurd life theories. The smug duo then mock him. Tonight Pilkington's subjects include an amusing riff on monkeys in space and a theory that 78-year-old humans should give birth as they die. Unfortunately what might work as pointless banter for the ears gains little when in cartoon form.

The Ricky Gervais Show is an animated version of the famous podcasts that featured Gervais, Stephen Merchant and Karl Pilkington sitting in a studio having the kind of free-range conversation that friends have in pubs in the last hour before closing time. When the show, which was originally broadcast in 2001 on Xfm, was released as a podcast, it was downloaded more than 250,000 times and won a place in Guinness World Records. The animation is somewhere between The Flintstones and South Park and the subject matter ranges from chimps in space to alternative methods of human reproduction. Many people enjoy its unstructured inventiveness. Others will dismiss it - in Gervais's words - as "the ramblings of someone you'd find in a hospital by themselves eating flies".

The collected musings of Ricky Gervais, ]Stephen Merchant and pal Karl Pilkington broke the Guinness world record for most downloaded podcast in 2007, so it's shrewd of HBO to recycle the audio and lay it over an animation. Here the trio are rendered like they're from a Hanna-Barbera cartoon and it's certainly a fun way to hear their banter once more. It will also put Pilkington on the map: he's supremely effective as the straight man while Gervais and Merchant mess around like naughty schoolboys.

TV has always helped itself to the best of other media, but this is new: a cartoon version of the hit podcast by Ricky Gervais, Stephen Merchant and Karl Pilkington. The 60s-style animations are beautifully done, with Gervais resembling (as he says) a cross between Barney Rubble and Fred Flintstone. But really, it should be called The Karl Pilkington Show. It's his deadpan idiocy that drives the fun, his riffs including the thesis that by 1900 everything worthwhile had already been invented (planes just take us to places we shouldn't visit). The other two mock and taunt him to the point of cruelty ("You are brain-dead! You are a maniac!"). It's like a surreal, blokeish pub conversation between old friends, overheard by Hanna-Barbera, and very funny.

If you are a fan of Ricky Gervais then you're probably also a fan of his podcasts. They became the most downloaded podcasts of all time, with something ridiculous like eight million downloads.

Technology has yet to come up with a word for what we should call it when old podcasts are turned into cartoons and then shown on TV.

If you watched Channel 4's Comedy Gala on Easter Monday - when Ricky, Stephen Merchant and Karl Pilkington contributed their thoughts on swimming with dolphins - you'll have seen how they, and their pointless ramblings, have been turned into Hanna-Barbera style animation. In short, it's genius.

The double bill of episodes shown tonight to kick off the series was recorded back in 2005 but given a new lease of life with the addition of pictures - and with Ricky Gervais drawn as a modern-day Fred Flintstone, they couldn't be fresher or funnier.

If this is all new to you, you'll find out tonight why Pilkington - the pair's former producer at radio station Xfm with the alleged perfectly round head - has been described by Gervais as the funniest man on the planet.

His deadpan musings on dinosaurs, monkeys in space, haunted houses and sexy metal pants are the backbone to these chats, while the other two laugh hysterically and shout him down as a gullible buffoon.

And now, for the first time, you can actually see what Karl's fantasies might actually look like. His mad theory on why air travel is intrinsically wrong, may also be of some comfort now to the millions who were affected by the volcano cloud.

The series started in the US a couple of months ago. What the Americans will have made to references to Derek Acorah, heaven only knows. Still, who cares? These three belong to us - a trio of national treasures. Fact.