Gmail users who are looking to add additional markers (other than text and color) to their labels should check out this article titled: Customize Your Gmail Labels with Unicode Characters.

This is a great idea as the author points out you can create logical groupings without and additional add-ons. Combine this with the ability to color code your different labels and it you have a pretty flexible organizational structure (think sub-folders).

Does anyone else have any Gmail organizational tips they would like to share?