env LD_PRELOAD=/usr/lib/libv4l/v4l2convert.so skypeyou can create a launcher with that as the "command" so you won't have to run from terminal every time.
MOAR from the wikipedia:
The dynamic linker can be influenced into modifying its behavior during either the program's execution or the program's linking. Examples of this can be seen in the run-time linker manual pages for various Unix-like systems. A typical modification of this behavior is the use of the LD_LIBRARY_PATH and LD_PRELOAD environment variables. These variables adjust the runtime linking process by searching for shared libraries at alternative locations and by forcefully loading and linking libraries that would otherwise not be loaded and linked, respectively.
I do not know what kind of code is in the shared object that we are loading, but it works for me :)