Google Instant: How Many Letters?

Search for something, anything on Google with “Google Instant” turned on (I believe it’s on by default).

How many letters did you type before what you were looking for appeared in the Instant results?

Example: “The Straight Dope” comes up after typing “the strai”

Cecil Adams: cecil a

Chicago Reader: chicago r

I’m bored: i’m b

Well something comes up first in the list for any single letter you type. I’ve not tried them all nor any of the higher ASCII characters, but I believe this to be true.