AIM encryption

Well, i wrote in earlier about the IP logging your convo, so i downloaded and put into effect the AIM encryption, but then i noticed that it isnt digitally signed. That doesnt bother me so much, but i also noticed that it uses the same password for everyone. Is the encryption worth it if the password could be found out anyway just by looking at a website? Also, is there a way to prevent IP packets from logging our convos? Or is there anyway a Personal Firewall could help at all? I dont know why, but this really makes me uncomfortable. I barely use the internet, but still, i wouldnt want anyone snooping on me when i am on. Thanks!:)