Picoblogorg now supports markdown formatting of posts. It's required by default unless you hack the code. I should probably add something to detect if markdown is available.
I am using the Discount markdown engine. I just call markdown directly when viewing the blog post to convert the markdown to html.
(de markup (Str) (let Line (pipe (out '(markdown) (prin Str)) (make (until (eof) (link (pack (line T) "^J")))))) Line))
It makes creating a long post much more efficient - especially when coupled with emacs markdown-mode