> I want to add to my application ability to capture
> photo from any USB camera
You would have to capture a frame for that from the media stream provided by the camera
>and signature from
> signature pad.
Just sometime back i remember someone posting a question on detecting a fingerprint from a fingerprint reading device. However there is no API which deals with hardware. You would need native code to read data from the signature pad ( use JNI ). Also search for some third part API for reading from a signature pad. With some luck you might stumble across one.