I had a quick look at one of the websites using it. It appears they aren’t doing anything you can already do with free fonts (or illegally with paid fonts).
The @fontface is supported by most (or all?) browsers with the only real issue being copyright infringement due to the font being accessible to anyone that knows where to look. All you need to do is upload a font to your server (making sure you can legally) put the @fontface call into your CSS...
@font-face {
font-family: "Robson Celtic";
src: url("http://site/fonts/rob-celt.ttf")
}
And then use the font as normal in your CSS...
body {
font-family: "Robson Celtic", Arial, sans-serif;
}
Too easy
As for using the site you mentioned, you’ll need to sign on to the website and then just copy and paste their css code into your css and you’re away. Just be sure to put alternate fonts in the css, othewise if their site is down your site will display with browser default font.
The other popular option for custom fonts is using
sifr. It uses flash to replace text with images, so only really good for headlines and the like. Personally, I’m not a fan of sifr, but until someone comes up with decent online font suport, it’s going to stay popular.
Cheers
Free