This junk mail with attitude is displayed - la Vision On - in a viewers' gallery that forms the centrepiece of the set for their new series. Commonly described as "Why Don't You...? for grown-ups with swearing", the series is, like so much BBC television comedy these days, a spin-off from a BBC radio show. Sitting proudly next to this gallery in the run-up to the series, Lee and Herring explain where they're coming from.
"We haven't set ourselves up as objective commentators," muses Lee, a broody indie-band type with a black "Bitch Goddesses" T-shirt and cheekbones to die for (you imagine much of his mailbag comes from teenage girls). "It's all done from the perspective of two blokes in their mid-twenties living in South London who haven't done a decent day's work in their life. Everything is filtered through that stupid world-view." Lee and Herring, who met at the Oxford University Revue, fight shy of a purely "yoof" tag.
"We're giving the viewer experiences about our lives which are specific for lazy, slacking dossers," says Herring, more of a roly-poly Country and Western figure in a purple collarless shirt and rich Cheddar vowels. "But the themes are universal - having to fill the empty hours of your life, lying awake wondering what the hell you're going to do, having crises of conscience. We've got this sketch about me being a vegetarian and having mice in my flat. How can I get rid of them without the moral responsibility of their death...? We don't want to alienate anyone by doing loads of jokes about Oasis or Blur, because older people won't get it. Similarly, we don't want to do loads of jokes about Swift - as John Sessions would - which you have to have a degree to understand. We really dislike all that clever-clever polemical satire."
Herring lays out their post-political manifesto: "We won't copy Monty Python," he asserts. "We'll do our own thing. When Reeves and Mortimer fail, it's a glorious failure because they've at least tried to do something different. I'd rather see them doing something rubbish than Rory Bremner's best sketch, because Rory Bremner's best sketch is still an impression based on a sketch from Weekending. It's like reading something out of the Guardian in a funny hat."
Fist of Fun is a self-conscious attempt at information overload, as zappy captions ("why not steal from the lower-middle class and give to the upper- middle class?"), flashed-up pictures - including a fetching one of Lee and Herring naked in a garden - and even Ceefax subtitles inundate the viewer with data. A video with a pause-button comes in handy. "We've tried to make use of the fact that young people are getting more adept at taking in information quickly," says Lee. "The wealth of options for your life is what Fist of Fun is about. It's about trying to stave off the meaninglessness of your own life by taking on hobbies, jobs and so on."
If this all sounds a bit philosophical, don't be put off; Fist of Fun is still well-endowed with knob gags. One posits the idea of the Pet Shop Boys running a hamster activity centre at their Shrewsbury mansion. "It's a physical weekend," says Herring, "so don't be worried if your hamster comes back a bit dirty and confused."
"All our characters will have sex with anyone or anything," Herring laughs. "It's about what it's like to be a politically correct man who's a bit confused about women. I'm the bloke who's obsessed with and frightened of sex at the same time. If Julia Sawalha [whom the Herring character fantasises about] did come and say, `Let's get down to the business,' I'd run away."
Lee and Herring used to share a house together and they are obviously as close off-stage as on. "We're pretty much the same," says Lee, "but because we spend all day together, we have to exaggerate the differences; otherwise, we'd just have no individuality. I don't really like smoking, but I have to do it to create a false difference. One of us has to smoke."
Being a pair of young, trendy comedians with, I hate to say it, a rock 'n' rolly following, Lee and Herring are inevitably compared to those other young, trendy comedians with a rock 'n' rolly following: Newman and Baddiel. "We're similar in that we both came from Radio 1 and we're doing a BBC2 show and we're two men," says Herring, "but they very much did stand-up stuff on their own. Half our show is about the relationship between us. Without saying we're the new Morecambe and Wise, which sounds just as bad, they very much had a relationship with levels to it. They disliked each other, but if anyone ever did anything to upset Little Ern, Eric would have a go at them. We're much more prepared to laugh at ourselves than Newman and Baddiel were."
Even after success on the radio with Weekending, On the Hour, Lionel Nimrod's Inexplicable World and Lee and Herring's Fist of Fun, the comedians are touchingly awestruck about having their own telly series while still in their mid-twenties. They swoon at the prospect of meeting Jeremy Paxman in a lift at the BBC. "We have to pinch ourselves every now and again," says Herring. "Like when we were at Richmond Park at six o'clock in the morning with 30 people, a milk float and three people dressed as Horsemen of the Apocalypse. You feel like saying, `It was only a joke. I'm sorry I've wasted your time. I'd no idea it would go this far. I thought someone would stop us'."
Still relatively new to the business, they cultivate the image of Slightly Irritated Young Men, opinionated outsiders determined not to sell out and become part of the backslapping Comedy Establishment. "It's like Absolutely Fabulous," says Herring. "I liked the first series, but in subsequent series, Jennifer Saunders has had the actual people she was parodying - like Zandra Rhodes - on to play parts. The minute you do that, it's not funny. It's like, `Look at me with all my mates'. You lose the power to take the piss once you're photographed with Naomi Campbell looking a bit smug about it all.''
They are equally zealous about not compromising themselves by doing adverts. "For the man who sent us those pants," says Lee, gesturing to the Y-fronts adorning the wall, "if we did an advert, it would be like when Shadow from Gladiators was discovered taking drugs."
The fans - with their pants and their till receipts - do seem to matter to Lee and Herring. "I got this really funny letter," Lee remembers, "saying, `I've listened to you on the radio for three years. It's great that you're going on telly because I'll be able to say I liked you first. I'll also be the first to say that you've gone rubbish now and sold out'."
`Fist of Fun', Tuesdays 9pm BBC2