$ virtualenv ipython
New python executable in ipython/bin/python
Installing setuptools............done.
$ source ipython/bin/activate
(ipython)$

(ipython)$ cd $VIRTUAL_ENV
(ipython)$ ls
bin     lib

(ipython)$ easy_install ipython
Searching for ipython
Reading http://pypi.python.org/simple/ipython/
Reading http://ipython.scipy.org
Reading http://ipython.scipy.org/dist
Best match: ipython 0.8.2
Downloading http://ipython.scipy.org/dist/ipython-0.8.2-py2.5.egg
Processing ipython-0.8.2-py2.5.egg
creating /Users/dhellmann/PythonMagazine/PythonEnv/ipython/lib/python2.5/site-packages/ipython-0.8.2-py2.5.egg
Extracting ipython-0.8.2-py2.5.egg to /Users/dhellmann/PythonMagazine/PythonEnv/ipython/lib/python2.5/site-packages
Adding ipython 0.8.2 to easy-install.pth file
Installing ipython script to /Users/dhellmann/PythonMagazine/PythonEnv/ipython/bin
Installing pycolor script to /Users/dhellmann/PythonMagazine/PythonEnv/ipython/bin

Installed /Users/dhellmann/PythonMagazine/PythonEnv/ipython/lib/python2.5/site-packages/ipython-0.8.2-py2.5.egg
Processing dependencies for ipython
Finished processing dependencies for ipython
(ipython)$ 
(ipython)$ which ipython
/Users/dhellmann/PythonMagazine/PythonEnv/ipython/bin/ipython