AIM, iChat, etc

[H. Peet Foster]

I need help in disabling AIM, iChat, etc on both my tibook and imac 
machine at home.

Here is the situation:
1).  Teenage daughter
2).  Addiction to AIM, iChat, admittedly as much a social necessity as 
the telephone, but not conducive to multitasking, especially homework.
3).  The ability to download and install the standalone AIM application 
without an administrator password.  (I had always thought that from 
system 10 and on, only and administrator could install app.s.  Not 
true!)
4).  The ability to change/add screenames, block and make oneself 
invisible, post profiles, personalities, troll the web with away 
messages, etc.

Okay, so this sounds like there are some control issues in my family.  
The reality is that I am more concerned about safety issues and helping 
my daughter to learn better time management skills.  Her current 
perception of "... just five minutes" to check email, or to ask (chat) 
a friend a homework question, can in reality be measured in hours.  Her 
"away" messages are a little too revealing to be posted on the web.  I 
am not against her expressing herself, but her perception that she is 
sitting securely at home at the computer contrasts to the reality that 
she is really broadcasting personal information to the world.  It has 
become a problem.

My thinking is that there must be a way to find out an disable only the 
ports involved for AIM and iChat.  This would leave email available as 
well as browsers and google searches necessary for homework research.  
I do not know how to do this as this does not seem to be possible in 
the firewall settings in system preferences.

Any help would be appreciated.

Peet