Note: These pages are deprecated in favour of the online documentation.
SciPy is composed of several modules under the scipy namespace. Here is a list:
Tools
Cluster : vector quantization / kmeans
Fftpack : discrete fourier transform algorithms
Integrate : integration routines and differential equation solvers
Interpolate : interpolation tools
Linalg : linear algebra routines
Misc : various utilities (including Python Imaging Library)
Ndimage : n-dimensional image tools
Optimize : optimization tools
Signal : signal processing tools
Sparse : sparse matrices
Stats : statistical functions
Other packages
Io : data input and output
Lib : wrappers to external libraries (BLAS, LAPACK)
Sandbox : incomplete, poorly-tested, or experimental code
Special : definitions of many usual math functions
Weave : C/C++ integration
You might also want to check out the SciPy API documentation