Yea, I evaluated jekyll, scanty, webby, aerial and a couple of other similar engines before making this, but none of them really worked the way I wanted.
I agree that jekyll's getting a bit heavy, although I'm definitely not even taking full advantage of all it's features. I still don't know much about Heroku though, and this might be a good way to try it out.
Rael Dornfest's http://www.blosxom.com/? I'd say that blazed the trail ~10 years ago for this type of software. I know for me at least, Blosxom was incredibly eye opening.
I've casually been working on a similar project except with PHP.
-http://github.com/breck7/brecksblog
-http://brecksblog.com
It's 1 file, under 250 lines of code, and powers a fair number of blogs now. Also uses a file for storage (no database needed).