Do a search on Highend for: geosphere.

T. Elser created a script called GeoSphere that has only been tested on v4 on NT.

He says:
When modelling low-poly objects Maya has a major disadvantage to 3ds Max: There are no GeoSphere primitives that have a lot less faces than those Maya polygonal spheres.
This script creates those spheres extremely useful for low-poly modelling: GeoSpheres based on an octahedron which means that they can easily be mirrored.
Code is based on a c program by Rick Bono where I took the basic formulae and calculations from.

You can specify geodesic frequency and radius to get the results you want.

Usage: GeoSphere [frequency] [radius] [polytype]

More information about usage, future improvements and known issues can be found in the script itself.

Update:
The new release 0.2 supports icosahedron and tetrahedron (tetra seems not perfectly working though - but maybe you won´t even notice the inaccuracy..) and it features a small user interface for creation of the spheres.
Update: 0.2 beta a fixes a bug concerning visibility of turned edges.
Instructions in readme.



ALSO

Adam Martinez created a plugin for Maya 4.0, NT/2K/XP called:
Super Ellipse and Super Ellipsoid.
They are two mathematical forms for a curve and a surface respectively.
It is only compiled for Maya 4.0 at the moment so that may not help you...