MyPho
Now I created my first app for android and uploaded it to the Market :).
It’s for free and really easy. The app contains 2 Buttons and one Textfield (duration) to change the settings.
In the background you can start and stop a serivce that will take pictures for the defined duration (Textfield).
Later I will add screenshots and a QR-Code so that you don’t have to search it in the market ;). By the way the name is MyPho if you want to search it in the Market.