I've been working on a tool to help with the creation of TileSets for a tile-based game in XNA. The TileSets are loosely based on the SpriteSheet created in the XNA Creators Club 'Tiled Sprites Sample' and allows you to load in a base texture, then define the various rectangles that represent your tiles. It goes a little further to allow you to name your tiles as well - no more having to remember tile indexes or sizes.

A handy re-sizable grid with 'snap-to-grid' functionality make it easy to drag out new tiles, and a nifty property grid allows for easy fine-tuning of existing tiles. You can even zoom your image to get a better look at things.

This uses the XNA Framework to draw the centre part - based off the WinForms sample.

If you think you may find this useful, you can download it here: TileSet Tool

I will be creating a custom content processor to automatically import TileSets into your XNA project for easy use.

Disclaimer: This tool is provided as-is without any warranty. It is an initial release and may contain bugs. If you find any, please let me know so I can fix them.