There's a restaurant in London where the menu has no prices. You pay what you think the meal was worth. Apparently it works well and it's rare for people to abuse the system.
w.bloggar is freeware but you're invited (non-invasively) to donate and become a "premium user". As I am a premium user I get to be the beta tester for new releases. The current release is v3 but I am writing this in v4 beta 1. Version 3 had a few of the problems you're likely to get with any one-man-band software but version 4 has ironed most of them out and is now a really powerful way of blogging.With some features still waiting for beta 2 I am excited.
Now, I now 95% of my readers aren't bloggers, but, if you are, you should give this nice little application a trial run. It works with the DomBlog API, that I believe is included with the popular BlogSphere template.