find(:all) problem

find is a class method, not an instance method.

Change
  b = @mystuff.find(:all, :select => 'mp1')
to
  b = Stuff.find(:all, :select => 'mp1')

Note: 'b' will be an array of ActiveRecords with only the mp1 attribute set.
If you want an array of strings, add:

b = b.map{|rec| rec.mp1}

HTH,
  Jeffrey

Quoting Mark Preston <rails-mailing-list@andreas-s.net>:
[snip]