The db:seed rake task in Rails is a nice addition and we use it a lot. The trouble is, you end up writing a lot of redundant code to check if records exist and stuff like that. Not very DRY, not very Rails.

Seed-Fu is a nice plugin that works very well, but it replaces the new db:seed rake task, and this solution is far more light-weight. You add another file to your db folder, seeds-helper.rb, and just require it at the top of seeds.rb.