Campaignr
Campaignr is a project I created for my Masters. It has since, and even during development, been used by many people who have needed to collect data using mobile phones.
It tasks mobile phones to collect data using all the sensors that a smartphone can provide: camera, microphone, gps, etc. as well as have the the person using the phone enter text. It uses XML to tell the phone which sensors to use, where to upload the data, and whether to collect the data on an interval or when the user pushes a button.
I have since moved on, and it has been taken over by other people back at CENS. More information and new versions can be found at the new Campaignr site.