can these commands be modified to use another encoder? is it possible to save as BMP instead of JPEG? and will that mean that we can take lossless photos w/o compression artefacts?

something that would be a real killer app for the N900 would be a MJPEG encoder for camcording purposes.
Recorded video will have huge file sizes, but it will provide a much more detailed picture and may also bring 720p capture possibilities (if the N900 flash rom can handle such speeds at saving data). Digital Cameras with weak CPU's usually perform very well recording video in HQ, when they are bundled with a good MJPEG encoder.

such a project bringing 720p capture to the N900 is so encouraging that i will try to improve mi knowledge of c++ programming and attempt it.