I'm reading "The Corporate Blogging Book" by Debbie Weil. She talks about two different types of blogs -- internal (Intranet-type) and external (public access) -- and she mentions how some big name companies use internal blogs for all sorts of purposes: knowledge/information sharing, email replacement, and, the thing that caught my attention, project management. Apparently IBM is big on all these things when it comes to internal blogs.
So I had a mini-revelation: an internal blog is a very good tool for tracking time you spend on various projects. Take the example of a hosting company -- it can set up an internal blog and have categories corresponding to various projects/customers; employees can jot down a summary of what they worked on each day, and put it in the appropriate category. After a while, a timeline of work done on particular projects emerges. Because posts are automatically dated, it's easy to see what you were working on 3 weeks or 3 months ago. And each blog post can contain links to more detailed howtos that are kept in a wiki which serves as a knowledge base. Blogs and wikis make entering information a snap, as opposed to more complicated project management/tracking tools. Blogs and wikis are also searchable, so finding information is easy. To me, this is a lean/agile way of keeping track of your work.
Anyway, maybe this is an obvious use of blogs, but to me it's new, and of course I'm going to implement it :-)