The first Drupal Camp North West is on the horizon!
I was recently working on a site where I wanted to use the '#states' key in a form using the Drupal 7 Form API. If you haven't come across this yet its a great way to only show a field depending on a certain set of circumstances.
How to create a simple multi-step form in Drupal 7, with forward and backwards navigation, per-step validation, and how to retain values between steps.
How to add a field to a content type programatically, using the field_create_field() and field_create_instance() functions.
How I made a basic mistake which lead to all of my URL's pointing at the base directory.
How to save the value of a field on a user, programatically.