Shoutbox

None for MSIE, but IE based browsers do have that option.

F.e. i use Avant and i got the following options (no need for a plugin, all is there standard):
Auto refresh the current: disabled, 10 sec, 30 sec, 1 min, 2 min, 5 min, 10 min, 15 min and the same options for All windows

I like Avant, it's fast, highly configurable and very complete in its options...