Letter by Letter JS is a lightweight jQuery plugin to present text letter by letter on a HTML page. This text can appear as if was just being typed, or it can fade in more gently.
Typer is a jQuery plugin for a slick typing effect. There are some option to customize plugin such as typeSpeed, typerInterval, typeDelay, etc.
TypeType is a jQuery plugin that simulates a human typing. It can be combined with jQuery animations.