Update: A more reliable modern way to access the right pip install for the right python install is to use the syntax python -m pip.
Original Answer
pip would install itself into the bin of your python installation location. It also should create a symlink to some more common location like /usr/local/bin/pip
You can either edit your ~/.profile and update your PATH to include /Library/Frameworks/Python.framework/Versions/2.6/bin, or you could create a symlink to it in a place that you know is in your path.
If you do: echo $PATH, you should see the paths currently being searched. If /usr/local/bin is in your PATH, you can do:
ln -s /Library/Frameworks/Python.framework/Versions/2.6/bin/pip /usr/local/bin
I would opt for adding the python bin to your $PATH variable.