I just came across this in Ubuntu 10.10 while browsing the Software Center.
I’m not sure how long this little feature has been available, but it sure does make promoting your favorite applications a breeze for Ubuntu users!
Clicking the linked text, as you can see, brings up a box to post to your “Broadcast” accounts (as Ubuntu calls them, otherwise known as your social networks). Here is an example of what it posts.
You’re free to edit the message how you see fit, with the important part being the “apturl:rhythmbox” token. For the record, there appears to be a bug at the moment that resets your edited message back to the default, but this will most likely be fixed.
I’m a little confused as to how this will work, since Firefox supports apt:application by default and not apturl:application. Also, Firefox requires the text to be a hyperlink, like the following examples apt:application and/or apturl:application.
If you find your browser unable to handle such links, you can find information here that should help you get them working.
I suppose this is yet another way that Ubuntu is becoming “social from the start!”