I\'m using Virtualenv with profit on my development environment with web.py, simplejson and other web oriented packages.
I\'m going to develop
Let's assume your virtualenv is named myProject and you're using virtualenvwrapper. A Unix platform is also assumed.
$ workon myProject
$ pip install --no-install SIP
$ pip install --no-install PyQt
$ cd ~/.virtualenvs/myProject/build/SIP
$ python configure.py
$ make
$ make install
$ cd ~/.virtualenvs/myProject/build/PyQt
$ python configure.py
$ make
$ make install
$ cd && rm -rf ~/.virtualenvs/myProject/build # Optional.