What the heck is ActiveRecord?

Gregg Pollack of Rails Envy has put together a great presentation about Active Record and object mapping.  The synopsis of the screencast is

• Who invented ActiveRecord and why
• How to use ActiveRecord
• Basic model to table mapping
• has_many relationships
• Magical counter fields
• Many to many relationships
• has_many => through
• Polymorphic relationships
• acts_as_taggable

It takes about 25 minutes to go through the video so if you have some spare time during a lunchbreak grab some coffee, a sub and educate yourself.  Enjoy.