Is it common to see directors acting in their own films?

There are a
few movies I can note where their directors also played a role in their films. Orson
Welles tended to star in many of his films, but that was during the 40's. Roman Polanski
played the role of the man who cut Jack Nicholson's nose in
Chinatown, but Chinatown was released in 1974.
The most recent film I can think of where this happened was when Quentin Tarrantinto
played Jimmy in Pulp Fiction, which was released in
1994.

I can't really think of any recent movies where
directors did this. Is it common to see directors acting in their own films these
days?

Answer

It is a very common occurrence. To quote a recent
instance, Jon Favreau played the chauffeur in both Iron Man and Iron Man 2. Quentin
Tarantino acted in Grindhouse, From Dusk Til Dawn, and had several other films. Clint
Eastwood appeared in Gran Torino and Million Dollar Baby. I could cite even more if I
could recollect year by year.

href="http://en.wikipedia.org/wiki/List_of_directors_who_appear_in_their_own_films">This
Wikipedia article could be of some help.