I’ve been using Firefox for about four years and they recently unleashed Firefox 3 which touts: Increased security, wicked-fast loading times, heightened security, and new UI improvements, including default themes for different operating systems and new download manager [wiki] not to mention basics like tabbed browsing and spell-checker.

I’m a fan of “add-ons” like the del.icio.us toolbar and Firebug, and I use to be all over themes although not since my days of being a Windows user have I truly tricked out any application or got a new skin for Winamp. Now it feels as awkward as peeling the backing and placing that first sticker on your pristine Macbook - some say it enhances while other say it’s simply ruined now. However, what I’m hearing lately is that the themes for Firefox 3 are pretty freakin’ cool, so I’m willing to try out a couple.

- There’s one that makes it look like you’re running Vista (if you’re on XP), and another that simulates XP (if you’re on Vista). These are also available on Kubuntu Linux.

- There’s also an XP on Vista with a green theme.

- Andy wrote about some sleek Mac-styled themes for FF3

- Pimpzilla (themed for my pleasure) is hilariously fun - and note the leopard print.

- CrystalFox Qute 1.0.3 is decent, although I like CrystalFox Modern a little more.

- From the Top Ten Firefox 3 Themes, there’s also the nicely rounded AzertyIII.

You can search for themes directly on the Firefox website and chose the advanced search properties to narrow down the results based on the version you are running.

Things to remember when looking for a theme a) is it available for the current version of the browser you are running b) is it available for MacOSX (which pertains to me anyway). If you have a favourite theme for FF3, drop a link in the comments below.

Update: Another form of customization is to change around the toolbars, giving you more browsing space. I found these tips on LifeHacker via Sameer Vasta over Twitter.