But first, ground rules. Click on all images in this post to see it full size. Uppercase "Wave" refers to the entire Google Wave product. Lowercase "wave" refers to an individual message or document. Think of a lowercase wave like an email or a Google Doc that you're collaborating on with other people. The screenshots in this post are from the Wave developer preview, not wave.google.com. We'll update this post with anything significantly new in the non-preview version when we get our grubby little paws on the proper server invitation.
Ready? Let's go.
Inside Google Wave
When you log into Wave, the default view is a three-column, 4-module layout. From left to right, the first column includes Navigation on top (think of this as your Inbox, Sent and labels in Gmail) and Contacts below (think of this as your GTalk buddy list). The second column is the list of active waves in your Inbox, and the third column is where you can start a new wave or open a wave.
Here's what it looks like. (Click to enlarge.)
When someone updates a wave in your inbox, it turns bold and moves to the top of your inbox — just like email. If a contact of yours is online, a little green dot appears on on his or her icon.
All the modules are collapsible and dock themselves in the upper part of the screen. If you've collapsed your inbox and a new wave gets updated, it flashes green. Here I've clicked on new wave and minimised all the other modules to expand my workspace. (Click to enlarge.)
You can add all sorts of rich content to your wave, like a YouTube video, Google Map, image, links or anything that a gadget enables. (More on gadgets below.) Here I've added some coloured text and embedded a video clip in my wave. (Click to enlarge.)
When I finish typing and click the Done button on my wave, Wave pops up the "Add participants" module so I can share my wave with anyone on my contacts list. You can search for a contact by name, or just drag and drop anyone to the wave you choose. (Click to enlarge.)
Once you've shared a wave, the magic starts to happen. At first you'll swoon over the ability to watch your co-waver type in real-time. It's weird in a good, we're-living-in-the-future way to see another person's cursor hard at work outputting characters, key-by-key on your own screen. But you get over that novelty pretty quickly. (Most likely your IM client can do that; anyone who's used collaborative editors like SubEthaEdit have seen this as well.)
You can reply to an entire wave like an IM or an email by clicking the reply button on a wave's toolbar. But what's most cool is the ability to reply to bits of a message inline. This lets you and your collaborators annotate the wave as you go.
For example, I gave a talk about Wave here in San Diego, and prepared my talk notes in a wave. At the beginning, I did an audience survey to gauge the level of experience with Wave-like technology. I was able to insert replies to the questions in Wave as I went. (Even better would have been to have a co-presenter or note-taker do that for me.)
You can collapse or expand inline comments easily. Here's what the talk wave looks like with comments collapsed. Notice the small talk bubbles on the top Audience survey section. (Click to enlarge.)
Here's what that same wave looks like with inline comments expanded. (Click to enlarge.)
Your replies inside or to a wave can also be marked as private; so if Jack and Jill and I are collaborating on a wave and Jill wants to tell me something about Jack in-wave that Jack shouldn't see, she can click on the drop-down on the upper right of a wave and choose "Private Reply" as shown. (Click to enlarge.)
Once you have entered your private reply, Wave prompts you to add participants to just that reply. That's because every reply is a wave in and of itself. You can create a new wave from any reply or copy a wave to a new wave, too.
The other "holy crap" feature of Google Wave is wave revision playback. If someone adds you to a wave late in the game, after lots of conversation and annotation has already happened, you can click on the playback button to see how it was constructed over time. Think of this like a slideshow through Wikipedia page revisions. Here's a quick video clip of what playback looks like on a wave I was in on this morning.
Wave Extensions: Gadgets and Robots
Wave is a completely extensible platform, like Firefox. Wave extensions come in two flavours: gadgets and robots.
A gadget is a piece of rich content that you can add to a wave. A few example gadgets are available in the Gadget gallery.
Click on the puzzle piece on a wave's toolbar to add a gadget to the wave. One useful gadget is the "Who is Coming?" gadget that lets you invite folks to an event and get RSVPs quickly and easily.
The most useful gadget I've seen so far is the Ribbit conference call gadget. Add it to a wave, and everyone adds their phone number to it. (You only see your own number, not everyone else's.) Click the "Start Conference" button, and everyone's phone rings — and you're on the phone, while you collaborate on a wave. (Click to enlarge.)
For more on the Ribbit Wave gadget, check out Rafe Needleman's review.
Robots are email addresses that you add to your contact list. Then, when you are in need of their services, you add a bot to a wave so they can perform some action on its contents. A robot can modify the contents of a wave, and several already exist that do silly to useful actions.
For example, Eliza the Robot Shrink ([email protected]) will chat with you about anything — useful when you're the only one of your friends who has a Wave invite and you've no one to talk to.
More usefully, the Bloggy bot ([email protected]) will publish a wave onto a Blogger blog for you. For example, I have Bloggy in my contacts, and added it to my Wave talk wave as shown here. Notice the "Bloggy published this wave here" message in yellow at the top of the wave. (Click to enlarge.)
Click on the "here" link and you go to my test Wave blog, which gets the contents of that wave on it. (Click to enlarge.)
If another Wave user happens upon that blog post, s/he can comment on it in-blog, and those new updates will show up in my Wave client. Right now, you have to be logged into Wave to see blogged content; but that won't always be the case. Google is working on making published Wave content read-only for all users, even those not logged into Wave.
Polly the Pollster ([email protected]) is another extremely useful bot which lets you create and distribute polls to survey wave collaborators quickly.
Other bots do things like automatically link Twitter usernames to their Twitter page, clean up empty replies (which proliferate quickly for some reason), and insert stock quotes. I expect we'll see tons more gadgets and bots bloom over the next year. Here are some more featured Wave extensions, courtesy of Google.
But What Will We Use Google Wave For?
The most frequent question I get about Google Wave is: "But what would I use it for?" Personally I can't wait to use it to take meeting minutes collaboratively and to co-write documents like blog posts and articles online with my editors and co-conspirators. Instead of using something like Campfire or IRC to chat with my fellow Lifehacker editors, I could see using Wave as group chat—but with inline and private replies, which are key.
Right now, like all collaboration tools, Wave is only as good as how many of the people you work (and play) with have it. Even though I was one of the developers touched by an angel, with access to the preview, I didn't actually use Wave very much because almost zero of my actual friends and co-workers were on it. So as far as I can see, uses for Wave in your life will open up as the product itself opens up to more users who care enough to wrap their heads around it and start putting valuable information in it.
Got questions about Google Wave? Post 'em up in the comments, and we'll answer what we can.