Here is an interesting* discussion of the Bacon number. According to them, there is at least one known film actor with an infinite Bacon number--Fred Ott (a Gary the Squirrel favorite, as some may recall.) Presently the highest known finite Bacon number is 8, shared by several obscurites such as William Rufus Shafter, a Union Army major general in the Civil War. Back in 2000, there were a few 9s and 10s.
Also, Kevin Bacon is not the most linkable actor in the IMDB. For a fun game, try to guess who is before you go to that article.
*"interesting"--that's an interesting word, isn't it?