Array#pack and String#unpack are broken on OS X Tiger's ruby build. This 
is known. I'm writing a lib where pack and unpack are used extensively 
and would like to provide a workaround. Does anyone have such a 
workaround already worked out? I can't think of a real easy way to do it 
so I thought I'd check before running the gauntlet.

See also http://hans.fugal.net/yodl/blosxom.cgi/mac/ruby-pack.html