Google Wave also . And what's not to like? The prototype promises the joining together of e-mail, chat, photo sharing and other forms of communication into a single online app.

At first glance, the "hosted" messaging system of Wave looks compelling. You can comment to a specific part of a conversation by dropping in your note right there in the message (rather than copying and pasting).

This feature looks great on stage, but I fear in practice it will result in confusion. It's sort of like how Google currently does Gmail. Unlike other e-mail systems, where the most recent message is at the top, Gmail has some mysterious system for how it orders threaded comments. I and others I've spoken to constantly find ourselves confused about where the most recent comment is. The thread feels shuffled.

Wave looks like it could make this situation even worse. After bouncing stuff back and forth, and after people comment on various parts of the thread, adding commentary at the top, bottom and middle of the original message, clarity about what's old, new, moot or relevant seems unlikely.