Ruby on Tiger
I've been toying around a little with Ruby lately, just to see what all of the fuss is about. While searching for some docs on the Flickr API, I discovered that Lucas Carlson of Technoblog has put together a unified shell script to fix the dependency issues with Tiger, including readline support and the rbconfig issues covered by fixrbconfig. Even if you've already updated your installation, fix-ruby-tiger.sh is still a neat little tool to have lying around.
For developers, the folks at Ruby on Rails are speculating that the latest Xcode update may have fixed the problem.