Good news for Python geo-programmers: Howard Butler has kicked out the jams, unstuck my Python/C++ R-Tree experiment, and allowed me to release Rtree 0.1.0. This package is based on Marios Hadjieleftheriou's spatialindex, and now allows you to persist a tree on disk. The one known bug is that it's a no go on 64-bit architectures. This will be addressed in the 0.2.0 release by using spatialindex 1.1.1.
In other news, I moved Rtree and Quadtree from Pleiades to the GIS-Python repository. Thanks to svndumpfilter, it was almost too easy.