Last night I was playing with a local group of players (another Dead band) that I get together with fairly regularly...It was an outdoor gig, and these guys have a tendency to stand there and audibly count off every single song.
I personally think it looks rather stupid, and have been pushing them to start off at least some of the songs without verbal cues, such as the guitar player just playing the riff, or the drummer giving a cue with his sticks, etc...I tried this last night..we finished one song and I started in with the next one, right away a song that actually starts off with a bass riff (Greatest Story), but these guys were having none of that and had me stop and count off and THAN start the song over....
Another thing I've noticed also is that I've seen a lot of people counting off passages inside of songs...there's one guy I know that I can even see his lips moving as he is counting off the passages...For a lot of this music I'm really not counting at all, at least not on a conscious level, I've got the song and lyrics playing in my head, but as far as actually standing there and going 1-2-3-4 in the middle of a song, thats something I am not aware of doing. Not saying anything is wrong with doing that...