I wrote a little program that generates all the combinations for a specified set and choice size; that is, it lists all the values of "n-choose-m". It's free, and runs on Windows, Mac, and Linux.
For instance, if you have eight players and need to list all the sports teams of three people you could make, this will do that.
Updated: you can now write the list of combinations directly to a file, which should help if you need to generate a very large list.
Updated (1/9/2012): you can set the names of the elements used to list combinations (for instance, to team names, player names, etc.)
Let me know (email@example.com) if you find this program useful, or if you have suggestions.
Here's a screenshot (click to enlarge):
You can download it from here: download (To run it, just double-click the .jar file you downloaded.)
Alternately, for Windows users, you can download a ZIP'd executable here: download ZIP
You'll need Java 5 or higher to run it. You probably have Java on your computer, but if not, it's a free download from www.java.com
* I use Michael Gilleland's code in this program.