Django installing packages via symlinking
If you can, it's better to include the packages as an svn external / git module / etc. That way they're always available, even to others that checkout your project.
Short of that, virtualenv is the better solution. You still "install" the packages, but they are added to the virtual environment (hence the name). You get all the benefits of packages installed right into site-packages, without actually adding anything to site-packages.
Is it possible to "install" third party django packages by sym linking them into your site directory? 
For example, I'd like to use the django-registration package. However, I don't want to install django-registration into my site-packages directory. I'd rather just link django-registration/registration into my project directory as /myproject/registration.  However, this doesn't seem to work. I get the following:
Error: No module named registration