> print everything I want until I su.  The username doesn't follow the user.  
> I'm setting USER=`whoami` and using $USER in PS1 to get the username.  
> I've also used `whoami` directly in the PS1 var.  No luck.  Is that
> because the su program on HP-UX isn't designed to update any env vars?  

check for a logname command if there is no whoami then these settings wont work.
My PS1 on a sco box looks like:
PS1='\u@\h:\w\$ '
This should be too much diffrent on any *nix running bash.
-- 
--
Bill Warner, aka Geekus Nosleepus No. 355122
Direct Alliance Corp.
Unix/Linux Admin.