I love many things about Sinatra, but it seems to assume that most of the applications built with it will be in a single file. That bugs me, and maybe you can help dispel this notion.
There are a few things I require if I'm to use Sinatra for my daily dev tasks:
The resources and match methods in Rails, combined with the standard RESTful method definitions make this easy. While I understand that's not necessarily DRY by some standards, it's certainly better than writing: