title: Python 2.7 on System, PIP and Virtualenv still using 2.6 - How do I switch them to use 2.7
body: <p>I am on MacOSx 10.6.8 and I have python 2.7 installed</p>
  
  <p>python -v produces:</p>
  
  <pre><code>Python 2.7.2 (v2.7.2:8527427914a2, Jun 11 2011, 15:22:34) 
  [GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  dlopen("/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/readline.so", 2);
  import readline # dynamically loaded from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/readline.so
  </code></pre>
  
  <p>I them run:</p>
  
  <pre><code>$ virtualenv venv
  </code></pre>
  
  <p>and then</p>
  
  <pre><code>$ . venv/bin/activate
  </code></pre>
  
  <p>and do a python -v</p>
  
  <p>and I get:</p>
  
  <pre><code>Python 2.6.1 (r261:67515, Jun 24 2010, 21:47:49) 
  [GCC 4.2.1 (Apple Inc. build 5646)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  dlopen("/Users/nkhdev/venv/lib/python2.6/lib-dynload/readline.so", 2);
  import readline # dynamically loaded from /Users/nkhdev/venv/lib/python2.6/lib-dynload/readline.so
  </code></pre>
  
  <p>Can someone tell me the steps to use have virtualenv create and use python 2.7 from my system?  Or have virtualenv, use python 2.7 period.  I don't care if the version is my system version.</p>