[whpalmer4]

If you have new enough hardware (iPhone 4 or later, running iOS 5 or later), you can set location notifications which trigger when you enter or leave a context. See the "Setting up Location Reminders" section of the built-in help.

Omni folk, is there a good reason why you don't have any online documentation for this feature yet? Even just a PDF file containing the images of the built-in help screens would be an improvement over nothing. If you do have such a document, why isn't it linked from the OmniFocus product page somewhere?