It’s an image. Fluther uses sprites to compress the amount of image downloading the user does with each page request. If you look at the sprite image the buttons are there.

Note that there are many ways to create buttons. Fluther’s CSS, for example, takes advantage of some WebKit-specific CSS rules and several other methods to create the button effect. Google’s new(ish) buttons do the same. If you look at Google using Safari or Chrome, the visual effect is accomplished entirely without images.

@noyesa – Now that is just the sexiest thing I have ever read.

@ChazMaz I do what I can. ;)

You can always use firebug (http://getfirebug.com/, Firefox add-on) to figure out how buttons are made. However, anything that has shading is usually an image since CSS can’t shade. Here’s a great resource for different button techniques: http://www.catswhocode.com/blog/top-10-css-buttons-tutorial-list