Jemgine.Hex now available for download
Our friend Blecki has released another project called Jemgine.Hex.
Here's some info from his codeplex project.
Jemgine.Hex implements a subdivideable hexagonal grid for XNA projects. Jemgine.Hex makes it easy to create hexagonal grids in vertical and horizontal orientations and to do mouse picking on them. It's written in C#.
All source is for XNA 4.0, but the library itself will compile against XNA 3.1 if it's references are changed. The demo project will not.
The HexDemo project contains examples of
*Rendering hexagonal grids
*Generating a series of subdivided grids
*Detecting the tile under the mouse of several subdivision levels
Please go check it out here
You can also see the Blecki's Jemgine XNA Engine which is a very fast maturing engine for XNA here