I plan on announcing this more fully later, but here’s my attempts at
creating a repository for higher quality/tutorial like rdocs for the
core.
http://wiki.github.com/rdp/ruby_tutorials_core
Feel free to check it out/add whatever you’d like there.
The thought is to have a high quality collection of rdoc supplemental
things there, then every so often convert them all to a gem [for easy ri
access] or commit them to ruby core itself.
I have found that having a reference like this is quite useful, and this
is an attempt to improve ruby’s documentation overall. Contributors
welcome 
Thanks!
-r