most of the guys around here use silkscreen for the small font in their signatures. If you meant the font on the icons that people make, that is usually done by creating letters with pixels.
I found a REALLY good site, with tons of pixel fonts. www.cubadust.com is where they are. Click the big splash button, then click the Fonts up at the top, and then click the Pixel fonts link on the side of the window that comes up.