Camera+ DV high res pictures?
Warning: high geekery follows.

When the UIPhotoPicker control (which manages still/video capture from the camera as well as selection of images from the image library) returns a camera image to the app that launched it, the image is at native resolution of the camera, which is Very Very Big. 5 megapixels at 2592 x 1936. 

An image object takes up space in the app's memory allocation, obviously. The amount it takes up is 4 bytes per pixel (r, g, b, and alpha). So an image at full resolution takes up 2592 x 1936 x 4 pixels: almost 20 megabytes. On a device that starts to complain if you take up (on the latest, beefiest version of the hardware) more than 30 or 40 mb. 

So the solution to that that most developers employ is to immediately scale the image down to something manageable, memory-wise, pretty much immediately on capture. An app that promised full resolution images would need to do nearly nothing else. It was only in the last couple versions of the hardware that we didn't have to dump a whole bunch of stuff from memory before going for a camera image.