Hi --
Inspired by a question from 'mickey' on IRC (mickey, where art thou?), I have written a plugin that lets you do class-style validations on individual ActiveRecord objects, like this:
t = Thing.new t.validates_size_of :name, :minimum => 5
and so on.
It's at http://www.risleydale.net/svn/plugins/singleton_validations/trunk
Enjoy, and let me know if any questions or problems.
David