Frequently amusing comedy that alternates Farrelly-directed ‘gross-out’ live-action sequences with colourful and inventive animation to good effect.

Bill Murray plays a total slob called Frank Dettori, who works as a zoo-keeper. In the opening scene a chimp snatches his boiled egg out of his mouth and Frank fights the chimp to get it back. It falls on the floor and Frank eats it, citing the "Ten Second Rule" - i.e. if it's been on the ground for less than ten seconds, you can still eat it…

From there we go inside his body - the animated 'City of Frank' and see the food arrive, bringing something Very Nasty Indeed with it - a new, deadly viral strain played by Laurence Fishburne (as ‘Thrax’). In a clever touch, he immediately kills a couple of white blood cells, making it seem like the opening to a cop thriller.

Which is fitting, because that's basically what this is - an animated buddy cop comedy thriller on the inside, and a live-action Farrelly Brothers Dumb-and-Dumber-style movie on the outside, although in amongst all the fart and vomit jokes there’s clearly something of educational value here for younger children, into the bargain.

The vocal talent are excellent: Chris Rock plays the brilliantly-named Osmosis Jones (cleverly ripping off Beverly Hills Cop) and David Hyde Pierce (Niles from Frasier) plays 'Drix', the neurotic 'rookie' Cold Pill Jones teams up with. There’s also great comic support from The Great William Shatner as Mayor Phlegmming, and Laurence Fishburne makes Thrax a genuinely scary villain.

The over-riding question with all comedies is ‘Are there many laughs in it?’ Luckily, the answer is yes - there are lots of great jokes, and not all of the scatological kind. The animation looks fresh and unusual, too, because most of the characters are blue and a lot of thought has gone into the ‘design’ of the City of Frank.

Similarly, Rock is a damn site better voicing an animated character than he is actually acting, as anyone unfortunate enough to have seen Down To Earth will be pleased to learn. (Even if he does refer to the female character by the actress' name at one point).

In short, Osmosis Jones has neat animation, several top laugh-out-loud gags, a great central idea (informative, no less), a superb vocal cast and Bills Murray and Shatner: together at last. What more could you ask for? Highly recommended.