Here are some of my wave gadgets. Instructions for adding a wave gadget to a wave can be found on the Wave Extensions Gallery help page.
An all-purpose* embedding gadget. Just paste in a URL for a video or sound and the gadget embeds it in the wave. You can embed content from YouTube, SoundCloud, Vimeo, DailyMotion, and more.
*some purposes may not actually be supported at this time
A miniature version of Google's Yes/No/Maybe Gadget. Like the Yes/No/Maybe gadget, just click one of the buttons to vote.
Google Like Button
A like button designed to look like those in Google Reader and Google Buzz.
Time Zone Gadget (beta)
Displays a set date and time in each user's own time zone. Useful for planning an event involving people from different time zones.
A gadget that allows you to do petitions in Wave. Some advantages of this are that people can see the petition text being written in real-time and personal information can be retrieved from the user's Wave profile, so the user does not have to type it in manually.
Instant “No” Button
Press in dire situations, cases of extreme disappointment, or when you just need a Star Wars reference.
Especially useful when your favorite wave service or MMO just got killed.https://raw.github.com/zmyaro/wave-gadgets/master/no/no.xml