I went into the sitting room the other evening to see what was on TV which was making my wife laugh her head off! Turned out to be the movie "Run Fat Boy Run". It was the scene where Simon Pegg is a security guard and is experiencing some personal discomfort! I sat down and watched the rest of the movie (which we had both seen previously) with her.
The moving is pleasant and heart-warming, and has some extremely funny passages. The scenes with both Pegg and and Dylan Moran are particularly funny. It is directed by David Schwimmer (who makes a cameo appearance) and I think it deserves considerably better than its current 6.6 rating on IMDB (it gets an even worse 5.4 from the critics on Rotten Tomatoes!)
I'm a big Simon Pegg fan (to the extent of following him on Twitter - the pretty intuitive "simonpegg"). I'm not sure where I first came across him but I suspect it was "Shaun of the Dead" first and "Hot Fuzz" second. I had missed "Spaced" completely but have since bought it on DVD - it's also very good.
To be honest I think I enjoy his out-and-out comedy roles most - although I am glad that he's had the level of success to enable him to work on "Mission Impossible" and "Star Trek".
Here's a shot from the movie showing Pegg's character struggling to compete with Hank Azaria: