02/07/2011 07:43 am ET | Updated May 25, 2011

Movie Review: Cedar Rapids

Despite some of the raunchiest dialogue in recent memory, there is an undeniable sweetness to Miguel Arteta's Cedar Rapids (opening Friday 2/11/11) that makes it hard to resist. The fact that it is consistently, inventively funny doesn't hurt.

Much of that sweetness - and yes, even innocence - can be credited to the performance by Ed Helms, as Tim Lippe, an innocent abroad, or as far abroad as Cedar Rapids is from his hometown of Brown Valley, Wis. Helms is the new master of playing naïve guys who aren't as dumb as they look but also aren't as smart as they think. He stole The Hangover from Zach Galifianakis and regularly finds comic gold in episodes of The Office.

In Cedar Rapids, from a script by Phil Johnston, Tim Lippe is a hometown boy who has made as good as he can imagine. He owns his own home (formerly his parents', one assumes), has a good job selling insurance - and is having what he thinks of as a love affair with the recently divorced woman who was his sixth-grade teacher (Sigourney Weaver).

But when one of his insurance colleagues turns up dead of unsavory causes, Tim's boss (Stephen Root) taps Tim to replace him at the regional insurance convention in Cedar Rapids. There, he'll give the presentation that his coworker was scheduled to offer, in pursuit of the coveted Two-Diamond Award, given only to the top regional insurance agencies.

Tim, who has never been on an airplane, is overawed at everything: from the strictness of airport security to getting a red rental Chevy to staying in a hotel that has an indoor swimming pool. He's a little intimidated by his roommate, a black man from St. Cloud, Minn., named Ronald (Isiah Whitlock Jr.) - until he discovers that Ronald is as big a nerd as he is.

Their third roommate, however, looks like trouble: Dean ("Call me Deanzy") Ziegler, who Tim has been warned away from (Ziegler allegedly tried to poach a client from Tim's dead colleague before the guy had even been buried). But Dean, played by the irrepressible John C. Reilly, is actually a pretty good guy - if a foul-mouthed, pushy bundle of bad impulses.

Still, most of what can go wrong for the well-meaning Tim goes wrong.