CSS Image Replacement
Using Background-Image to Replace Text - Stop Design
This is the original image replacement tutorial that started it all. It is not recommended for use because it makes the hidden text completely inaccessible in certain situations. It is included here for reference and historical purposes.
Image Replacement - Mo Jebus
Seamus Leahy came up with a way to drop the extraneous span tag and replace text with images. This site currently has some issues in IE 6.
A new image replacement technique - As Days Pass By
Stuart Langridge came up with the same idea as Leahy, but this site is more like a tutorial. If you learn better by hacking at examples, go to the Leahy site above, if you learn better from tutorials, go to this site.
sIFR - Scalable Inman Flash Replacement
Facts and Opinions about Fahrner Image Replacement - A List Apart
Joe Clark writes an article discussing the pros and cons of using image replacement, especially FIR. If you're curious how FIR works with screen readers, look no further.