New versions of Tweetdeck, Seesmic square off

There's a new version of the Tweetdeck Twitter client, 0.26, launching tonight, following the earlier release today of a preview of Seesmic Desktop 0.3. Both updated Twitter clients look like significant improvements from their previous versions. Tweetdeck is also getting an iPhone app.

Tweetdeck 0.26

The big new features on the Tweetdeck side are synchronization and multiple account support. The sync feature means that users who have Tweetdeck on multiple computers won't have to re-create their groups and search queries on each computer. They'll log in, instead, to a new Tweetdeck account, and their Tweetdeck client will automatically download the saved data from whatever installation of Tweetdeck they last ran.

Tweetdeck is also getting multiple account support. The lack of that has become a greater issue for Tweetdeck as more marketers and Twitter power users experiment with different online personas. The client continues to support Facebook, 12Seconds, and a few other networks. It also gets support for viewing Qik videos in the client itself, and for replying to them.

Tweetdeck won't store Twitter passwords in on its servers, but other than that, the sync feature will also replicate users' account settings across installations.

The sync feature will also connect to the new iPhone app. You'll be able to swipe to change columns, and the client will ready your saved searches and groups from your desktop Tweetdeck installations. The iPhone app has been in limbo in the Apple approval process for about 10 days, Tweetdeck creator Iain Dodsworth tells me, but he hopes to see it released to the app store soon. Kevin Rose got a preview.

Also coming in Tweetdeck: a new column for Tweetdeck newbies that highlights Twitter accounts recommended by Tweetdeck staff. Like Twitter's own recommended accounts list, it could help new users get started in the network, and make a big difference for the Twitterers who get a place in the column. Dodsworth is aware that there are issues around fairness and transparency on the Twitter default list, and he says he's open to experimenting with it. "If people flood us with [financial] offers to include them, then that may be the next test," he told me.

My take, based on a conversation with Dodsworth but no actual hands-on experience with either of the new Tweetdeck apps: The sync feature is key to locking users into the client, since it increases the value of each installation of the app for busy, multi-machine users, and by that I mean anyone with a computer and an iPhone. Dodsworth likes lock-in, as any smart CEO would. His vision for Tweetdeck is that, "It's a platform. It's a browser for the real-time Web."

I'm a multi-computer Tweetdeck user and am looking forward to trying this new version. It should be available tonight, 9 p.m. Pacific Time.

Seesmic Desktop 0.3

Tweetdeck challenger Seesmic Desktop is now in its 0.3 version. A younger app, this client is showing more differences between versions than Tweetdeck, and it's getting markedly better in each. Seesmic has also supported multiple Twitter accounts for longer than Tweetdeck, and the new client makes short work of posting a tweet to one Twitter account or to several, or to Facebook as well. There's also a nice tweet entry box that automatically shrinks unless you're typing in it. That's a nice space-saver that makes up, in a small way, for the way the client still hogs the left-most pane of the app with a list of accounts, groups, and saved searches. While that part of the interface is clear and useful, when I'm on a small laptop I do wish I could get it back for content.

Facebook users will find more features for them as well, including support for adding comments to friends' updates and a quick way to "like" posts.

Seesmic now also includes support for personal Bit.ly accounts. Almost all Twitter clients, including Tweetdeck, let you post short URLs using Bit.ly, but Seesmic Desktop is the only I know that will access your personal account on the service, from which you can see stats on all the short URLs you've created.

Version 0.3 also fixes bugs, like the previous version's tendency to want to reply to a Twitter post with a Facebook message, and is generally slicker and more enjoyable to use.

The Seesmic Desktop 0.3 version I tried is a "release candidate" and can be downloaded directly here. Existing users' installations of Seesmic Desktop will not auto-update to this version until later in the week, Seemsic CEO Loic LeMeur told me.

Which one?

Tweetdeck and Seesmic Desktop are both freaking great Twitter clients. Seesmic appears to have a bit more horsepower for dealing with multiple accounts and Facebook, but I still find Tweetdeck's single-account Twitter experience slightly more enjoyable. If Tweetdeck delivers on the synced multi-computer support tonight, and the iPhone support ends up being is as good as I'm hearing, it will make it very difficult for the mainstream Twitter user to move off of it.

Both developers continue to update their apps, though. So this battle is far from over.