gaussian, grayscale, highpass, invert, laplacian, prewitt, rgb, roberts, saturation, sepia, sharpen, sobel, thresholding, lowpass 3x3, lowpass 5x5
It is also completely library independent and can be safely used next to NodeJS, jQuery, YUI, Scriptaculous, MooTools, etc.
pixelate.js is a simple library and jQuery plugin to pixelate any set of images and optionally reveal them on hover.
Image Color-Up is a jQuery plugin to add effects on mouse hover to your images: monochrome/greyscale, sepia, negative, darken or lighten images.
tiltShift.js is a jQuery plugin that uses the CSS3 image filters to replicate the tilt-shift effect. This is a proof of concept and currently only works in Chrome & Safari 6