As you probably know, we’re in the final countdown of Jay Leno’s tenure on the Tonight Show. The genial funny man says goodbye on May 29th and, if you’re old enough to remember back that far, it’s hard not to recall the late Johnny Carson’s final evenings in the Burbank studio.

Aside from being an Academy Award-winning actor (The Usual Suspects and American Beauty), Kevin Spacey is also known for doing some pretty great impressions, most notably Christopher Walken, Jack Lemmon and Walter Matthau.

Spacey also does a pretty good impression of Carson and has performed it for David Letterman a couple times. Last night, Spacey did a few minutes of his Carson impression for Leno the other night — complete with props. Take a look…

Here, Spacey explains how he approaches doing impressions and his Carson one in particular.

Image courtesy NBC.