Two people who hate each other end up falling in love - it's a well-trodden formula of romantic comedies. To make it work though, you need at least one of the characters to be mildly endearing - without that, it simply becomes a story of two obnoxious tools becoming one annoying (and frankly dubious) couple.

That's what you get with 'Vegas', a threadbare story of a slacker and a career girl who end up stuck in a marriage together that neither wants. Added to this is a potential several million dollar reward for whichever of the two gets the other one to initiate a divorce. Instead of behaving like rational adults in this situation however, the two decide to basically make the other's life a living hell.

Whilst the setup may sound ridiculous, it is reminiscent of 1989's "The War of the Roses" - Danny DeVito's deliciously black and relentlessly cynical comedy about the increasing feud between a divorcing couple. Whereas that film engaged in some truly subversie and clever acts of one upmanship (remember the dog pate?), here we simply get some almost cartoon-like school-level pranks of missing toilet seats and ignoring important phone calls.

Both a help and a hindrance are its stars who are in many ways surprisingly suited for each other. Both Ashton Kutcher and Cameron Diaz share similar traits - they're 'stars' rather than actors and more known for their looks than actual talent (though neither isn't without some reserve of ability to be sure). They both have had experience in the rom-com field before, and both can effectively come off as juvenile brats which makes their pranks more credible.

Yet while Kutcher plays a well-kept immature slacker, something he can do without breaking a sweat, Diaz as a high-flying Wall Street shark with an obsessive nature for scheduling is far less believable. She looks good in dresses though and the film frocks her up in some memorable blue and gold numbers at different points. It's also surprisingly equal opportunity on the flesh front with Kutcher spending much of the film shirtless and/or in boxers.

Brief appearances by Queen Latifah as their court-appointed marriage counselor highlights the fact that even with only a few lines of dialogue, she has more talent than the rest of the surprisingly small cast combined. The script commendably keeps the film tightly focused on the dilemma of the situation and doesn't try to include other complications of murky subplots (short of the decent minor story of Diaz's ex-fiance).

Once the film tones down its wild histrionics and begins to give these characters a bit more weight in order to establish the romance, there is something more here. The formula is too contrived and the chemistry not enough for any genuine sparks to fly, but what started out as a simply annoying pairing becomes something more tolerable by the end. Only sporadically funny, not particularly well made, and too tame to offend or delight - this really is a one night stand you'd rather forget.