A program I am fond of, especially as an artist, is FontMatrix. This program is easily found is the Ubuntu Software Center, making installation a breeze.
I had originally used Fonty Python to manage my fonts (nice name?) but the program is limited. The newest version of FP allows for only 10 fonts to appear per page. When one has 500+ fonts, it will take forever to find the right font for the task you are working on.
In comes FontMatrix which offers an array of abilities. First, you are able to see your fonts in a preview list. I love this feature. You can scroll through your fonts quickly to find something you like. You can tag favorite fonts to easily find them. Reading the font information is helpful as well as comparing fonts is made easy. The glyph page and playground make this program special.