Quick heads up, for anyone who uses sounds in your builds. iStockAudio launched yesterday. You can grab thousands of royalty-free clips, from sound effects to music, and pay for them using iStockPhoto credits. It's 2-25 credits for most clips, depending on length and complexity, from what I've seen so far.
The search engine on the site isn't the greatest, but you can usually find what you need if you treat it nicely. I'm sure it will get easier as the service grows, and more and more clips are added.