We got to try the Ribbit and 6rounds extensions first-hand over the last few days and they have turned out to be pretty interesting.

The Ribbit conference call extension allows you to quickly set up a teleconference in Wave. Calls can be routed to any phone, and you can use the wave simply to provide context for the call or to keep notes. Because Google doesn't currently give developers direct access to contact information, you have to type in your own number, but otherwise the operation couldn't be any easier.

While Ribbit focuses on telephone, the team at 6rounds has built a video chat gadget. Currently, 6rounds supports only one-on-one chats, but even given this limitation, the app builds nicely on Google Wave's real-time emphasis and allows you to watch YouTube videos or play games with your friends.

We didn't get to test the Lonely Planet, AccuWeather and LabPixies extensions yet, but they all look pretty useful as well. When we talked to the Wave team earlier this week, they especially raved about LabPixies Sudoku game, which looks to be quite addictive.

A Few More Things to Do When You Get Your Wave Invite

• Invite your friends. You will be able to nominate up to 8 of your friends for a Wave account. Wave is a lot more fun when you have somebody to help you test it.
• When you start a new wave, click on the Google icon. From there, you can add links and search and embed YouTube videos and images.
• Try to add a map (just click the Google Maps pin). As you scroll, everybody else in the wave will see a live update of what you are doing.
• Need to vote on where to go for dinner tonight? Try the Yes/No/Maybe gadget.
• Try the 'playback' feature - it replays a wave step by step. This comes in really handy if you want to check who has made what revisions.
• Invite a robot to your wave. Just add elizarobot@appspot.comto your contacts, for example, and you will have a robot shrink to chat with while you're waiting for your friends to sign up.

And a Few More Things to Remember

• Wave works in most modern browsers (and even runs on Safari on the iPhone), but it works best in Google Chrome (IE users will be prompted to install Chrome Frame).
• To add a contact to a wave, just start a new wave and drag and drop the icon from the Contacts sidebar to the new wave.
• The blue lines that appear when you scroll through a list show you where your reply goes. Just click on the line and a reply will show up.
• Pressing 'Enter' will take you to the next line in your reply - you have to hit "Shift + Enter" to finalize your reply.
• Private replies are hidden in the pull-down menu at the right edge of the message that you are editing.
• Stuff will break - remember that this is a very early beta!

Feel free to post a comment if you have additional tips and tricks (or favorite robots and extensions) you would like to share.