I have not added ~/bin to any of my .bash* files. However, $PATH does list that directory.
The reason I am asking this in the Ubuntu specific StackExchange is because, well, I have exactly the same .bashrc, .bash_profile and .bash_aliases in both Fedora and Ubuntu machines (in fact, I have them on Dropbox and symlinked in ~) and in my Fedora machines, ~/bin is not added.
In other words, if I add ~/bin to my path by making an entry in .bashrc, it shows up once on Fedora and twice on Ubuntu.
Where is ~/bin being added to my path?