Basically, any time a site gives you a snippet of code that includes "< iframe >", you can retrieve the URL and use it with the Iframe gadget. Here's another example of how to embed a Google presentation in a wave. First, click "Share->Publish" on the presentation, then copy the URL from the Iframe code there and paste that into the Iframe gadget, making sure it's tall enough to show the controls.

Even if the site doesn't give you an Iframe embed code, you can still try embedding the page URL and see how it looks.

To get started with the IFrame gadget, sign into Google Wave and install it from here.

Additionally, if a site gives you a snippet of code that uses an "<embed>" or "<script>" tag (equating to a Flash or JavaScript widget), you can use the HTML gadget, by the same author, to embed that site in a wave. To try that one out, install it from here.

We hope this helps you integrate more content into Google Wave.

Posted by Pamela Fox, Developer Relations, Google Wave Team