Free Globes is open source, php/mysql based web directory script with Digg like features, where users can vote for sites they like. I haven’t tested it yet, but looks like there are a lot of features available.

Script and web site are in Franch, but here are few links to get you started:

FreeGlobe Demo

Download page

Available themes

Installation guide

English support forums

Example sites using FreeGlobes

I find this script perfect for starting a niche directory and might give it it a try very soon. Anyway, just wanted to share my discovery with you.