Social networking application Yoono released new versions of both its desktop app — Windows, Mac, Linux — and its Firefox add-on this morning.

The company likes to point out that the add-on is downloaded more than the toolbars for social networks StumbleUpon, Facebook and Digg combined, according to the live stats at the Firefox add-ons directory.

More interesting to me is that on Facebook, active monthly users of the Yoomo Facebook app now number 89,277. Compare that to Seesmic’s 24,809 and TweetDeck’s 2,820.

Of course, all these numbers ignore the fact that Seesmic and TweetDeck users vastly prefer the Adobe AIR-based desktop/laptop applications and the iPhone apps for these tools. Also, they use them primarily for Twitter rather than Facebook. I don’t see many tweets marked “1 minute ago from Yoono” compared to the every-few-seconds posts from TweetDeck. Seesmic tweet frequency seems about the same as Yoono. And Digsby, a desktop tool that merges all status updates into a single IM-like window rather than covering the screen, has 112,788 Facebook users.

Still, Yoono’s numerical successes prove that those of us who think the whole world is fighting over Seesmic-vs-TweetDeck are missing potential rivals like Yoono and Flock.

I’m not big on browser add-ons, especially since I’ve switched away from Firefox to Google Chrome. I installed Flash and that was it. But I think social network consoles like Yoono, Seesmic and TweetDeck are powerful productivity boosters and stress reducers for heavy Twitter and Facebook users.

I wrote a feature-length article on these tools for The New York Times last year. A 24-year-old Comcast employee I interviewed, @comcastbonnie, used TweetDeck, then switched to Seesmic, to crank out 400-plus replies to customer tweets daily. She was so prolific, Twitter blocked her. They thought she was a bot.

San Francisco-based Yoono was founded in 2008, and received $4 million in funding in a June 2008 round that included AGF Private Equity.