If you’ve been following the micro-blogging service Twitter and it’s 140 character limit isn’t quite what you want, you might consider Tumblr. Tumblr equates themselves with a “scrapbook”, provided you consider weblogs to be “journals”.

However you can’t really call Tumblr a precise alternative for a number of reasons. One is that you can give the appearance to visitors that your tumbelog is hosted on its own domain by redirecting the IP address. Also, a tumbelog really is more like a mini weblog. Techslut even shows you how to integrate your tumblelog (and Twitter tweets) into your WordPress setup.

If you do decide to “self-host”, they warn you that they’re not in a position to help you configure your tumblelog, so you should  ask a friend. On the other hand, if  you set up your tumblelog the regular way, there’s less headache and you get a subdomain.
Here’s my tumblelog, which display diagrams that I’ve created for various weblogs that I either write for or own. (What I should have done is provided a link to each article, so each diagram could be seen in context. In which case my tumblelog would be an index to my slice of the blogosphere.)

Features of Tumblr

Here are some of the other features and functionality of Tumblr tumblelogs:

1. Themes. Customize appearance by editing the HTML and CSS. You can even borrow theme fragments from WordPress, though you’ll have to do the conversion and twiddling yourself.

2. Content variety. Easily post several types of content: articles, quotes, links, IM conversation text, photos, and videos. The latter two can be from Flickr and YouTube; just specify the link.
3. Moblogging. Post photos from your cell phone by mailing them to a secret email address set up just for your tumblelog.
4. Bookmarklet. Post quickly using the bookmarklet. Depending on your web browser (I’m running Firefox), you can drag the bookmarklet to your Bookmarks Bar. Then, whenever  you’re on a page that you want to Tumble, just click the bookmarklet. The content type defaults to a link, but you can change that.
5. Twitter integration. Integrate your Twitter tweets into your tumbelog. (I haven’t looked deeply into this. It might amount to using the Tumblr bookmarklet to post while you are still in Twitter.)

The interface is pretty easy to use, and the text editor is WYSIWYG. However, some of the functionality doesn’t work properly in the Firefox browser. (Try adding a hyperlink to some text.) Like a blog platform and Twitter, Tumblelogs have RSS feeds with which friends can subscribe. Your feed can be full text or short, and sites like Technorati and My Yahoo! can be pinged whenever you add a new post.

What you Cannot Do With/In Tumblr

Here’s what you cannot do:

1. You cannot send or subscribe to Tumbelogs by SMS. At least not that I could see in the Tumblr FAQ.
2. You cannot pull in web feeds to generate content.
3. You cannot actually host the content on your own server. Again, not that I could see.
4. You cannot interact with other Tumblrweeds (or whatever they’re called). I.e., there are no social networking features.

So in essence, Tumblr is more like a Blogspot service than a Twitter service, but with some interesting features that make it different enough. Call it mini-blogging instead of micro-blogging. Tumblr has made it easy to post a small range of content types. It’s much more stream of consciousness than Twitter because of the content types supported, but it’s not a replacement.

What can you use it for?

I can already think of a number of uses for Tumblr that Twitter simply cannot fulfil:

1. A scrapbook. Or create a family photo album for family and friends, complete with captions or little snippets of conversation (copied from an IM text chat session).

2. Personal portal. A portal/index to all your posts, if you blog at multiple places.
3. Lens. Alternative to Squidoo lenses. Tumblr’s not an authority domain yet like Squidoo, but it could be soon.
4. Mini-blog. Burn the feed in Feedburner and use their BuzzBoost HTML/Javascript badge to display the content as a mini-blog on an actual blog, in the sidebar. So you can produce “what I’m reading/ listening to” lists on your blog, without having to upgrade your theme.

Missing features

Being a geek, I’d like to see a number of features that would round Tumblr out:

1. Social features. This might include comments, or some sort of ability to interact with other Tumblrweeds.

2. Audio. Embedding of audio files, for podcasting or for recording messages in a family photo album.
3. RSS feed importing. Tie-in with RSS feeds in a variety of ways, including importing, to generate content. This would be a very nice display vehicle for some custom Yahoo feeds.

Overall, I’d have to say I like Tumblr, at least for mini-blogging. My head hurts with ways I could use it.