window split from tag?

[Lev Lvovsky]

When following a tag through to the file where it's defined, is there  
any way to get vim to keep the existing window open, and simply open  
(vertically and/or horizontally) a new window as opposed to replacing  
the existing one?

Also, somewhat related - I'm using the TagList plugin, and I'd like  
to have all windows but the tag list (which I'd like to keep narrow)  
at a specific width - rtfm pointers appreciated ;)

thanks!
-lev