Styling Sites the Way You Want Them
If you're a user of Firefox and comfortable with downloading and installing extensions, you can customize the look of almost any site on the web using the Stylish extension provided by the good people over at User Styles. Aside from controlling many aspects of various websites, it also allows you to change the way Firefox in general looks, such as adding Safari's rounded user bars to Firefox.
How It Works
Stylish works as a CSS replacement for most sites. When your browser calls a website, a stylesheet is loaded that defines how the website should look. What Stylish does is overwrite this call for the stylesheet, replacing it with it's own stylesheet you've defined. The best part is, if you've made no call for a different stylesheet, the default one is used. Best of all, you can choose to preview a style before actually installing it, so if you don't like it, you can choose to cancel and no changes will be made. Pretty nifty, huh?
You can use Stylish on any number of sites you'd like to change by visiting Userstyles.org and checking for the existence of a style for your site. Some of the more popular sites to style include Google, Gmail, YouTube, DeviantART, MySpace, Yahoo… the list goes on and on. Just about any major site you can think of will have a style created for it.
Where To Get It
Stylish is available at the Mozilla Extensions website. As for the styles for both the Firefox application, as well as various websites, you can find them at User Styles.
Some of the more popular styles to download for Stylish on Userstyles.org include:
Google Dark - Transforms Google searches for websites, images, videos… all to the dark grey you see. This grey version is very easy on the eyes, unlike the current white version which is like staring at a bright light bulb. This style is great for users who prefer dark CSS over that of light; especially great if you use a dark Windows XP theme.
DeviantART Blue - Tired of the same old green theme on DeviantART? Change it! This theme is a nice subtle blue with yellow links which is easy on the eyes and great for those who prefer a bit of a darker image than most websites provide.
Wikipedia - Really hate the way Wikipedia is laid out, with the search function half way down the page? This changes it drastically so that it's not only more easy to read, the search function is much more accessible.
As you can see, this is only a selection of what you can find on userstyles.org. There are many more great styles you might find to suit your needs, and if you find you need to switch a style off, you can simply right click the icon in the taskbar and uncheck the style. It's as simple as that.