If you do a lot of writing on the web you should check out Markdown.
Markdown is a way to write for the web in plain-text. It’s very similar to the conventions that people used on Usenet ages ago. You can basically write HTML markup without having to write a whole lot of HTML.
I have written a whole lot more since I started using Markdown. Case in point:
Tumblr and Typepad support Markdown. WordPress (dot org, not dot com) needs a little convincing. Blogger does not support Markdown.