I’m not aware of any, but then I wouldn’t necessarily be – this is probably the first mention of Joomla i’ve seen on these forums 
The reason I am asking is that I work for a K-12 school district and we recently made a big push to using open source software. We are using Joomla for the main district website, Deki Wiki for each of 32 school websites, Moodle for online learning, WPMU+BP for about 650 teacher blogs, PHP Motion for video sharing, and an additional install of WPMUBP for student created blogs which is private.
http://dearbornschools.org
Check out iBlog for BP, D-Tube for PHP motion, or visit any of the school websites for Deki Wiki. Moodle is iLearn and requires authorization to get in.
If there is anyway to further integrate BP and Joomla, please let me know.
BuddyPress is based on WordPress, which as you probably know can be used as a CMS too. Therefore, it is not likely that any effort is made in tying together Joomla and BuddyPress.
However, it shouldn’t be too hard to create a “special page” in buddypress/wordpress that outputs some data (XML, serialized PHP, or something) about the logged in users that can be fetched with some kind of Joomla extension at regular intervals.
How about outputting an rss feed based on get_online_users()?
