[sunburnt]

Each top-level conversation contains groups of messages that are sort of like subthreads. The conversations are referred to as "waves" and the subthreads are called "wavelets". Individual messages, which are called "blips", are the smallest discrete conversational unit of a wave. The distinction between Wave the service and "wave" the conversational unit is significant, so keep an eye on the capitalization.

Why the jargon? These terms do not relate to anything anyone is familiar with in any different context. This seems unnecessary.

I genuinely hope that http://xkcd.com/483/ (Fiction Rule of Thumb) doesn't apply to Google Wave.

[pohl]

Sorry for the pedantry, but doesn't expecting the terms to relate to things in a different context go against the very nature of jargon?

Jargon is "technical terminology unique to a particular subject." [wiktionary.org]

I imagine that when one is discussing OTs and how they relate to the federation protocol, these terms would be very useful. Sure, you could talk about nodes and edges in a graph, but there are many graphs of many types in any large system. These terms refer to specific kinds of nodes in a very specific kind of graph.