"Do you have any protection?" is the poser that floors sacktime novice Andy (Carrell) at the point of his first sexual gratification. "I don't like guns," he replies.

Andy is the good-natured but sexual innocent who works at a hi-fi and TV store where Michael McDonald has been playing on the shop's plasma screens for the last two years.

He's happy observing a self-imposed life of celibacy at his bachelor flat with his PlayStation, collection of mint condition boxed toys and walls adorned with framed Asia posters.

However, when his co-workers learn that he hasn't lost his cherry, they charitably see it as their mission to ensure his four-decade dry spell comes to an end. So to speak.

Their first piece of advice is to pick up a drunk chick in the form of Nicky (Leslie Mann), who drunk drives him home before barfing a seafood sandwich over his head.

Undaunted, Andy's subsequent efforts to meet Miss Right are doomed to failure... until he sells quirky Trish (Keener) a video recorder.

A yummy-grandmummy, she runs a store opposite that sells your unwanted junk on eBay if you can't be bothered...and she sees Andy as more than an untouched curiosity.

Carell, who co-wrote the script with director Judd Apatow, is destined to become a comedy great with this splendid debut lead role as his calling card.

Boasting the best of Ben Stiller and Jim Carrey, he manages to be both serious and comic at the same time and displays the comedy timing of an atomic clock.

British audiences will know him as the American version of David Brent in The Office but scene-stealing roles in Anchorman and Bewitched have hinted at what he's capable of.

It helps that he's got sterling support from the likes of Keener and his non-PC approach ("he's got more video games than an Asian teenager") comes as refreshing change from comedies hidebound by liberal sensibilities. And it's bloody funny.

You'd be mad to miss it.

Tim Evans