Google Wave was a comprehensive solution packaging real time document collaboration, chat, communication (and what not) in a single tool. A “feature rich” product. But it failed miserably.
Twitter is the simplest possible Internet tool/protocol I have ever used. It allows you to share your thoughts with your friends if you can fit them within 140 characters limit. Nothing more, nothing less. Twitter is growing by 300,000 new users per day.
Long live simplicity.