Originally Posted by decodedthought
to search the software source for a package.
otherwise you could give him your sourcelist
# gedit /etc/apt/sources.list
copy the whole list and paste in a new text file.
If it's in a PPA? packages.ubuntu.com seems not to search them.
This seems a rather basic function - "Oh, I have that installed? Where did I get it from? I forget." I find it surprising that the local apt utilities don't have a way to handle that.
@Matthew: By source, I meant the package repository
from which the package was downloaded, not source code.