On my linux (Ubuntu 11.04) development machine. I often need to install libraries from source. This always causes problems for me because the package manager doesn't consider packages installed from source when it checks dependencies. This makes the package manager worthless to me since once I install one set of libs from source (especially if they are vital to the gnome environment i.e. gstreamer), I can never use it again without screwing up my entire distro with mixed dependencies. It seems to me that it would be relatively simple to check the dependencies with pkg-config without having to worry with the deb database. I don't mind writing a little code here. Does anyone have any ideas?
Alternatively, you should look into the equivs package, which is made exactly for the purpose of creating empty .debs that will make apt/dpkg think a certain package is installed when it isn't.