Evan - Thanks for MarkdownPad. It's shiny, the UI is so transparent that I hardly notice it's there, and it makes writing just plain fun.
I'm currently using MarkdownPad as a replacement for the Zim desktop wiki, which I formerly used for simple documentation. The standardised Markdown syntax is a great plus - I already use StackOverflow, so it means I can use the same Markdown syntax as SO instead of having to learn yet another lightweight markup format.
Again, thanks for MarkdownPad, and keep up the good work!