Here's a little gem I've been working on that just might be ready to show it's face in public:
http://github.com/jedediah/print_members/tree/master

For the most part, the info comes from Ruby's reflection features but it also parses source files to get method parameters, which is surprisingly non-slow.
The gem can be installed directly from github:
I'm taking suggestions for a more fun name.
http://github.com/jedediah/print_members/tree/master
It's an interactive doodad for Ruby 1.9 that probes a class/module and shows you just about everything there is to know about it, in pretty colors. I find that about every second or third line I enter in IRB is a call to this thing.
For the most part, the info comes from Ruby's reflection features but it also parses source files to get method parameters, which is surprisingly non-slow.
The gem can be installed directly from github:
gem install \ --source http://gems.github.com \ jedediah-print_members
I'm taking suggestions for a more fun name.