Sidekick (hiptop) let you interact with your AIM contacts for basically free, at a time when many people were still paying 30 cents apiece for SMS messages. The

Sidekick (hiptop) let you interact with your AIM contacts for basically free, at a time when many people were still paying 30 cents apiece for SMS messages. They even had a data only plan. I knew a bunch of deaf kids around that time and they all were enthusiastic Sidekick users.