Earlier this week we learned that short messaging service Pownce was closing shop. I shared some of the reasons I believe it closed. For a long time, Pownce was considered the second most popular short messaging service behind Twitter. With the Pownce closure, I started to wonder...who's next to be acquired?Jaiku was acquired by Google last year and has remained in a private beta since. I rarely ever hear anyone mention Jaiku anymore; most likely it's due to the private beta status so you can't get your friends onto the system. Jaiku has message threading (similar to Pownce) along with groups (something Twitter says is coming). The Jaiku Web site is pushing its mobile features, so perhaps there will be a tie into Google's mobile aspirations. Clearly, Jaiku won't be acquired but could face the same path as so many other Google acquisitions: perpetual private beta.

Plurk says it is a "social journal" and the big difference between Plurk and Twitter is the use of a vertical time line that shows how people are interacting with your content stream. Plurk also uses a "karma" system, which rewards users for activities on the system. There is some popularity with Plurk users, but the general buzz factor seems to have died off. Most of the friends I have on Plurk seem to have left as well. The time line view that Plurk utilizes might be worth integrating into a blogging platform, so WordPress or Tumblr could acquire the service/talent in a transaction similar to the Pownce transaction.

Brightkite is a location-based social network. This means you provide updates to Brightkite about where you are at this moment and Brightkite shares the updates with your friends. The idea is to meet people who also are in the general area where you are. When Brightkite launched I couldn't go a minute without getting an update from a friend. Now the updates have slowed to one or two a day. During my time in grad school, I designed a system very much like Brightkite and still believe it could be a winner once they can get into the full mainstream market. As for acquisition options, Brightkite would be a good fit for Nokia.

The last service I'd like to mention is identi.ca. This short messaging service is different than the others as it's got open source elements and uses Creative Commons licensing. I don't see identi.ca being acquired anytime soon, but with the tech geek community it's gaining in popularity. The popularity comes from the open source element plus the ability to use your own servers with the service. Identi.ca also uses a push protocol named OpenMicroBlogging to get your messages out past the walls of identi.ca.

There a number of other services in the space including Swurl, FriendFeed, and SocialMedian. These are mainly aggregator services, which I don't see as acquisition targets in the near future.