iPad app for collecting door-to-door survey information? I need to be able to develop a custom form so I can have workers go door to door and collect survey information.  Think census workers, but geared towards the upcoming election.

While I could develop a custom app, I expect to have to customize it heavily for each area, and make changes to the forms throughout the process.

In order to control costs we're not going with 3G service, so all the form data has to be collected on the device and saved until it's uploaded via wifi network (or any other method) later.


Are there any apps that let me design my own custom fields for form entry, and save the data on the device?  
Simple database apps with custom forms or similar?


If I had my wishlist, it would also:


Automatically download the latest collected data when in range of a network.
Update a standard database server directly (MS SQL, Oracle, MySQL, other?).
Track the location the info was collected (difficult and imprecise, probably, since it's a wifi tablet only)
Allow hundreds of tablets to check in and upload to the central server at any time, including simultaneously
Prompts the survey recorder with a script - not just a form, but gives them what to say, what to ask, and leads them through a configurable tree of questions, some of which depend on previous questions answered.  For instance once they indicate their political affiliation, it might skip questions not appropriate to save time.
You could use Bento for iPad. It allows you to create custom databases with great looking entry screens. It will also store information on the device until you sync it again.