I too have not considered what the Guest Account means or does, until now. Snow Leopard.

Looking at System Preferences > Accounts, I have four entries:-
Brian Ferguson - Admin [where Password & Login Items are available. Also Login Options.]
Brian .me - Admin [if needed]
test - Admin [if ever I needed it] and

Guest Account - and the permitted-items change depending on what selections you make, from:
   1. Allow guests to log in to this computer - [On] or [Off]
   2. Allow guests to log in to this computer - [On] or [Off]
with the four alternatives yielding:
   * Login, Sharing - 1 On, 2 On
   * Sharing Only - 1 Off, 2 On [my normal selection]
   * Login Only - 1 On, 2 Off
   * Disabled - 1 Off, 2 Off.

Under the Accounts List, the two boxes [+][-] also change. 
With either My Account or Guest Account selected, the [-] button is greyed-out, therefore I assume these Accounts cannot be removed.

In any case, why delete the Guest Account?
It does nothing subversive.
   
------------------------
Regards from brianF
===============

On 14/09/2010, at 6:22 PM, Doug Browne wrote:

> A terminology problem here Kino, which is my mistake. Since my computer is normally only used by me, I have set automatic login. Syst Prefs -  Accounts shows my name and administrator. Under that is "Guest Account Disabled", as you say. I am sure this is default behaviour of OS 10.6.4.
> 
> The login window, which I do not normally see, is similar to yours.
> 
> As I am the only user, I do not need the Shared folder:   Macintosh HD - Users - Shared. 
> But this is another thing that always reappears after trashing.
> 
> Doug
> 
> On 14 Sep 2010, at 08:54, Kino wrote:
> 
>> On Sep 14, 2010, at 3:45 PM, Doug Browne wrote:
>> 
>>> I never thought about it before, but I also have 'Guest Account Disabled' under my name.
>>> I have just run Kino's instructions below, but after a restart 'Guest Account Disabled' was still there.
>> 
>> Do you mean you see it in the login window? Mine looks like this.
>> <http://images.macworld.com/images/legacy/2006/08/images/content/login2.png>
>> 
>> If it is in the Accounts System pref that you see "Guest Account Disabled", it is normal.
>> <http://db.tidbits.com/resources/2009-10/Disable-guest-account.png>
>> 
>> But I don't know for sure if the login window's showing "Guest Account Disabled" is really odd or not. Perhaps that is the default behaviour for those who have enabled just a single account? Since 10.6.4, maybe. I'm and have been running my Macs always with two or more accounts enabled and I have never seen the login window of anyone else's Mac.
>> 
>> Also perhaps whether you have /Users/Guest or not would make a difference. If you have disabled Guest Account, I think you can trash it (you will be asked to enter your admin password) and empty the trash safely.
>> 
>> 
>> Kino