Sinatra is a wonderful lightweight web framework for Ruby developers. It has a very simple DSL syntax (an example is provided on the homepage). With it, you can write a complete web application (albeit a simple one) in a single Ruby file!
But when you expand your source into a few files and combine it with the excellent Ruby ORM library DataMapper, you can accomplish some pretty cool stuff and avoid the bloat of a large framework like Rails.
I re-wrote this website in Sinatra in May. I’ve enjoyed being free from the oppression of common web programming language that shall not be named. You can browse the source code of my site here. One resource that came in particularly handy when getting starting was ididitmyway.heroku.com. Give Sinatra a try and see what you think. If you think it’s wonderful, I’ll agree with you.