Diaspora*, the free, open source, decentralized, non-profit, user-owned, distributed social network that is based upon the free Diaspora software, can also be used as your public blog, website or publishing platform,

After signing up and configuring your Diaspora account, all of your published posts marked as public will be then made available at your own Public Diaspora URL, a URL in the format of https://yourdiasporapod/u/yourusername; mine, from the screenshot above, is available at https://diaspora.happeningin.eu/u/rovemonteux.
There are no limits for the size of the posts, you can upload multiple images + videos all together in a single post and photos will come up in a lightbox-like/slideshow interface, you can categorize the posts using hashtags, and the process of creating new posts, uploading pictures and posting videos is both intuitive and effortless.
You can then add your own internet domain name to your new blog/website, or redirect entries from your existing domain, like, say, blog.myname.com, to https://yourdiasporapod/u/yourusername, and effectively use Diaspora this way as your daily publishing software (Diaspora also have a mobile interface, making it also a Mobile Publishing Platform).
A simple and effective way to accomplish it when using the Apache Web Server is to use a mod_rewrite rule,
RewriteCond %{HTTP_HOST} ^blog.myname.com$
RewriteRule (.*) https://diaspora.happeningin.eu/u/myusername [R=301,L]
When buying a domain (.com, .net, .info, .co.uk, etc), you will also be offered a free “URL Forwarding” option – this option will enable you to forward your domain to your public Diaspora page in minutes, even if you have no web server nor hosting account, making the only expense for the entire process the cost of your fully qualified domain itself, for the entire lifetime of the domain.
Or, alternatively, you can use a free fully qualified domain, such as the ones offered by dot.tk, what will result in something similar to http://myusername.tk/, http://myusernameblog.tk/, or any name domain at your wish plus the .tk; they will also give you a URL forwarding option, making everything absolutely free.
Live example: http://rovemonteux.tk/ and https://diaspora.happeningin.eu/posts/197.

Each individual public post will be then made available for index and inclusion in search engines such as Google, Bing, Yahoo! (this feature is disabled by default in most Diaspora pods – your pod need to enable it for it to become public, see note at the end of the post), and each individual entry will appear alone, in its own dedicated address as an individual entry in searches, or as a collection of posts in a blog-like page in the root of your new domain.
Please note that none of your non-public posts, ie. posts not marked as Public at the time of publishing, will be available to the internet, thus will not be available in your new address and/or Public Diaspora profile. Posts marked as Aspect-only (default) only reach people you authorized to be in the same Aspect (group), and only.
You can also publish a Public post from inside Diaspora to Twitter, Facebook and Tumblr all in one go, after you setup the external services at Profile->Settings->Services (https://diaspora.happeningin.eu/services).

Below is a screenshot of a post of mine on Diaspora (the video is automatically rendered after posting the YouTube address, and clicking the camera icon enables you to easily upload and publish as many photos as you wish at once), and you can format messages ie. name links, use bold and italic nested or in their own, quote text, etc (see https://github.com/diaspora/diaspora/wiki/Message-Formatting),

And the same post automatically published to a Facebook account,

More information
Diaspora @ Happening in EU
podupti.me
Note for public Diaspora pod hosts and users: Edit your robots.txt file and remove the /u/ rule to enable the indexing of public user pages and posts; the same is enabled on Diaspora @ Happening in EU (https://diaspora.happeningin.eu/robots.txt). No private profile information, gender and location is ever made public, and users can disallow indexing and search for their own accounts in profile settings (https://diaspora.happeningin.eu/profile/edit).
Update, 20th of December 2011: The following is a screenshot of a Google Search for “Rove Monteux Stream of Passion“; it shows my public Diaspora stream with a preview, the post mentioned in this article with its correct publishing date (“2 days ago”), correct title and description, tons of Google +1 buttons around them all, and as I have lots of contacts in the developer’s Pod joindiaspora.com, the third result is a copy of this same Public post that automatically went to tag stream “Metal” in that Pod,

Update, 21st of December 2011: While going through Diaspora’s source code, I have find out that the maximum length of a post in Diaspora is 65535 characters; that is enough space for a very long blog-like post. Tumblr have a 1000 characters limit, Twitter 140 and Facebook 420.

48.804380
16.626685