Ubuntu – Apache2 – Limit download speed

You're looking for mod_cband to do what you need. You wrap it's directives inside a LocationMatch container for .gif files for example. If for some reason you're running an old Apache 1.3 look up mod_bandwidth or mod_throttle instead.

http://codee.pl/cband.html

ps aux | egrep '(apache|httpd)' typically will show what apache is running as.

Usually you do not need to change the default user, "nobody" or "apache" are typically fine users. As long as its not "root" ;)

edit: more accurate command for catching apache binaries too