Online bidding begins on Monday and closes on 26 September. The winner will join Ferrell on the set of Step Brothers and appear in a scene.

Proceeds will go to the Cancer for College foundation, set up by Ferrell's university friend and cancer survivor Craig Pollard.

Ferrell's previous films include Wedding Crashers and Blades of Glory.

"What a perfect Christmas present for your son or daughter," Ferrell said.

"It is the surefire way to win the parent of the year award. Support this amazing cause by buying them me."

2008 release

The winner will be announced on 27 September and will meet the actor the following day at a golf tournament dinner in aid of the charity.

Mr Pollard, who overcame Hodgkin's disease twice as a teenager, set up the charity to provide college scholarships to current and former cancer patients.

Cancer for College has awarded $200,000 to 50 cancer survivors since 1993.

Step Brothers, due for release next year, stars Ferrell and Adam McKay as two spoiled sons who become competitive stepbrothers when their single parents marry each other.  From BBC

That would be really cool, but you know it's going to go for a ridiculous amount that us the little people could never afford.  Mind you be a bit rubbish if it went for £10 I suppose.  Also, bet anyone form outside the US has to pay for their own air fares...

What film would you bid to be in?  (No Porn Movies SoD)  Me it would have to have been Ghostbusters... Or Lost in Translation.