Number of categories:
Number of values per category:

Group 1
Item 1: Item 2: Item 3: Item 4: Item 5:

Group 2
Item 1: Item 2: Item 3: Item 4: Item 5:

Group 3
Item 1: Item 2: Item 3: Item 4: Item 5:

Group 4
Item 1: Item 2: Item 3: Item 4: Item 5:

Group 5
Item 1: Item 2: Item 3: Item 4: Item 5:

Clues:
This tool has been tested on Firefox 26, Chrome 32, and Internet Explorer 8.0. It works as designed on all three, but on IE it is not very pretty. It requires JavaScript, so if you are having problems with it, please make sure that JS is enabled in your browser. The source code, and other neat things, are available at www.phrebh.com.