Requests for your upcoming Validations Screencast

Hi Ryan-

Your first two screencasts with the Pragmatic Programmers are great.
I am looking forward to your upcoming screencast on validations.
I also enjoyed your railscast #41 and #62 on validations.

I am hoping you may include some information on a few areas that I don’t quite understand fully.

How does this work and in what context should I use it.
validates_presence_of(:address, :if => Proc.new {|a| a.create_step == 8})

In what cases and how do I use with_options for validations.
The Rails Way book mentions this on page 493, but a more in depth coverage would be useful.

An update to your episode 41 on Conditional Validations would be quite useful as well. Is this still the best way to do this in Rails 2.1?

If you ever need a reviewer you have a volunteer here.

Best Regards-

Charles