When it comes to microblogging, the first word that pops into everyone's mind is Twitter. Twitter will always be the heavyweight simply because they were first. Twitter should be just one of your primary microblogging tools. We all know what happens when we keep all our eggs in one basket. Listed below are six great twitter alternatives. These should be used in combination with Twitter. One more thing to keep in mind is updating. You can use web based apps to update all your microblogging profiles in one shot. There are also Adobe Air/desktop applications such as Posty that work just as well.

1) Identi.ca

Identi.ca was launched in July of this year. It gained traction quickly, partially due to it being the first open-source Twitter clone. It came on the scene at a time when Twitter's service suffered from extensive outages and service limitations. Twitter users flocked in droves looking for a stable alternative.

Features:

• 140 characters limitation
• Open ID
• SMS capabilities
• (XMPP based) instant messaging client IM updates
• Crossposting to Twitter
• Option to automatically follow back new subscribers
• Adobe AIR/various desktop applications

It's a win win situation for developers and end users:

Identi.ca is open-source, open data, has an API, and can be federated.

2) Rejaw

Rejaw is an interesting microblogging platform. Unlike Twitter, you are not bound by 140 chars, you have a spacious 1,000 character limit. The ability to post images and video is a major plus. The user interface is simple, easy on the eyes, and easy to use. I particularly like the use of big fonts and big text implemented on the site. It's a definite welcome for the visually impaired.

Features:

• 1,000 characters limit messaging
• Ability to post videos and images
• Threaded conversations
• Permalinks
• Guests can comment on threads, no registration is necessary.
• API for developers

3) Jaiku

Jaiku is currently a Google property, since Google acquired them in Oct of 2007. It's very comparable to twitter, with a 140 character limit. It offers a lifestreaming element by allowing you to add your blog, photos, and other RSS or Atom feeds to your stream.

Features:

• 140 character limitation
• SMS capabilities
• (XMPP based) instant messaging client IM updates
• lifestreaming capabilities
• Adobe AIR/desktop applications
• API for developers

4) Tumblr

Tumblr is a microblogging platform abundant in features. It is highly customizable and is suitable for short form blog posting. There is no commenting system, but a third party application such as Disqus can be implemented. Along with posting messages, you can also post and share an assortment of media. You also have the ability to use a custom domain name. Overall, Tumblr blogs are easy to set up, maintain and should suit your basic microblogging needs, with a ton of bells and whistles.

Features:

• No character limitations
• Ability to post audio, videos and images
• Customizable
• Email posting
• Bookmarklet posting
• IM updates via AOL Instant Messenger.
• lifestreaming capabilities
• RSS output feed
• Adobe AIR/desktop applications
• API for developers

5) Kwippy

Kwippy started out as an IM status aggregator. It has since evolved into a microblogging platform. It's similar to Twitter with more of an emphasis on IM updating and aggregating. It currently lacks any mobile options. There is also an API, which I'm not sure has been publicly released yet.

Features:

• No character limitations
• Convenient commenting on status messages
• Instant messaging updates via Gtalk or Yahoo Messenger
• Facebook statuses intergration
• Threaded discussions
• Permalinks
• RSS output feed