Setting up your MacBook for ROR

I am getting my new MacBook today and was wondering if the experts on
this list might have some tips and pointers about what they do to set up
their Macs as a RubyonRails dev machine?

I come from a windows background and some of this is essential there.
But in the case of Macs do you recommend,

* installing the OS from scratch
* adding/removing any default applications from the install
* any other system/OS level tuning

I do intend to use the Hivelogic/Geoffrey Grosenbach's tips to get the
Ruby, Rails, MySQL, Mongrel setup done. Suggestions/comments welcome.

I happen to like X11 as an environment for development (editors and shells,
primarily, with various OS X apps for other things) so I installed X11 from
the install DVD. You'll also need the developer tools (XCode) from the
install DVD so that RubyGems will be able to compile extensions.

I used Fink to install most everything (Ruby executables, my editor, and
various convenient libraries, such as ImageMagick) RubyGems, then installed
RubyGems by hand. From there it was a gem install.