Web 2.0 categories

I've found several attempts to categorize web 2.0 applications. Some are interesting but unmanageable, such as 50+ categories found at Centre for Learning & Performance Technologies. Others seem to leave out quite a bit, such as that found at ReadWebWrite:

Blogging (briefly includes wikis)
Podcasting
Media sharing
Social networks

And some seem to include services that seem web 1.0ish or antithetical to many of the open principles of web 2.0, such as the listing of classroom management software at Hubpages.

So here's how I plan to categorize and explore more closely web 2.0 applications in the next couple weeks. It seems inclusive enough to my viewpoint, however warped that might be:

Aggregators--combining several processes onto one web page, including mashups.
Examples: iGoogle, Pageflakes, Netvibes

Media sharing--photo, video and audio presentation.
Examples: Flickr, Youtube, podcasting

Social networks/virtual environments--places online where people socialize, converse, work together. I considered separating these two, but they seem to serve similar purposes. I may change if I find the distinctions clearer.
Examples: Facebook, Myspace, Second Life

Collaborative/social publishing--primarily the sharing and editing of text.
Examples: blogs, microblogs, social bookmarking, wikis


These seem both manageable and inclusive.

By the way, the html editor in Blogger really sucks--it does squirrelly things when you try to edit. I had to paste a a plain text version into the "Edit Html" tab and then reformat to make things look decent here.