First, download and install version 1.7.0 of the libspatialindex library from:
http://libspatialindex.github.com
The library is a GNU-style build, so it is a matter of:
$ ./configure; make; make install
You may need to run the ldconfig command after installing the library to ensure that applications can find it at startup time.
At this point you can get Rtree 0.7.0 via easy_install:
$ easy_install Rtree
or by running the local setup.py:
$ python setup.py install
You can build and test in place like:
$ python setup.py test
The Windows DLLs of libspatialindex are pre-compiled in windows installers that are available from PyPI. Installation on Windows is as easy as:
c:\python2x\scripts\easy_install.exe Rtree