Some Interesting Jetpacks
As of now, the Jetpack library only features a small number of extensions. Users can browse Jetpacks by tag, author and popularity (though the most popular Jetpack (a Google Wave add-on) currently only has 24 downloads. Nonetheless, quite a few interesting Jetpack add-ons have already found their way into the gallery. These include a tool that translates text with Google Translate, a browser-based image editor from pixlr that can be invoked from the right-click menu in Firefox and a plugin that displays tabs with thumbnails in the left sidebar.
Give it a Try
To get started with Jetpack, you have to install the Jetpack plugin first. After that, just head over to the Jetpack Gallery and install a few of the plugins. To manage the installed Jetpacks, point your browser to about:jetpack.