Similarly, anything you've installed in that virtualenv that installs itself in a bin folder (pip, mercurial, django-admin.py, etc) will be in that bin folder,

Similarly, anything you've installed in that virtualenv that installs itself in a bin folder (pip, mercurial, django-admin.py, etc) will be in that bin folder, and calling them from that directory will execute them in the context of that virtualenv as well.