I remember when they were trying to push the .CC -- turned out to be a big nothing.

.CO is worse, IMO -- because everytime you transmit (online or verbally) the name, you are going to have to EXPLAIN that it's NOT .com (a typo). This will be more trouble than it's worth -- people will naturally go to the .com version, assuming the .CO was a typo.

Unless you want to cybersquat some big names/words to hold them hostage, hoping other people will pay your ransom to have them released -- because they are afraid of people accidentally going to .co, because they typed it as a mistake (misspelled, basically).

-- TW