One thing that gets overlooked and may be the reason even running the removal tool doesn't always work, is disabling Auto Protect and Script Blocking and anything else in Norton's Options before beginning to uninstall.
As far as how it works or what it does, in simple tems it cleans up the registry more thoroughly than the regular installer. And also it reverses a protection mechanism available thru MSI, among other things.
You may still have some leftovers--I've seen the Symantec Core LC service leftover in a lot of HijackThis logs and they will usually leave folders (and maybe some files) in Program Files and C:\Program Files\Common Files\Symantec Shared
that can be deleted manually.
You really can't tell how a Norton uninstall is going to go. From what I've seen, I'm just about ready to believe the best way to get rid of it completely is to reformat, but that may be overly pessimistic as Norton may have improved its removal tool.
Norton has also been known to mess around with the BITS service--don't know if the uninstall tool now deals with that or not. I used to have a site bookmarked about that but am having trouble finding it, but this should do: http://www.runpcrun.com/symantec-norton-removal
Papakid will check under the mattress and other cubbyholes and post back when he finds the other article.