I must admit that I’d never used IR on a site until today… my client wanted pretty H1 tags and Georgia wasn’t cutting it. So I did a little research and found that CSS-Discuss recommended the Gilder Levin Ryznar Jacoubsen (Version 1) technique to be one of the most accessibility-friendly; scroll down about 2/5 of the way to read more about this. Here’s the page with the technique spelled out for you.
This was super-easy to implement in both the HTML and CSS. It took me about 20 minutes to change 15 or so H1 headings to the new images and the client is now happy.