Ajaxian talks about an interesting way to use Google Gears for sites that don't necessarily integrate with Google's toolkit for offline applications: inject code using Greasemonkey. An article shows how you can save a number of Wikipedia articles for offline use, without depending on your browser's cache.

Sites with a lot of static information -- Wikipedia, any API documentation, web-based email -- would be great to be able to use when no internet connection is available. But what if you're a user that always has an internet connection? Then adding Gears to a site doesn't do much, right? Wrong. Imagine your favorite website is now stored on your computer, and it syncs whenever there's altered content. Whenever you look at the site, your browser is grabbing everything straight from your hard drive. Did you just make a search for your best friend on Facebook? Don't wait 5 seconds the next time that search runs, have the results immediately! Meanwhile, save the webmasters' precious bandwidth/server power!

Here's the Greasemonkey script for Wikipedia (requires Firefox + Gresemonkey + Gears). For each Wikipedia article you want to save, click on "cache page" and the script will save the text and the images. It would be nice to make it work with any site.

</img> </img> </img> </img>