Resource Saving Tips

Good advice all around. Another thing to be careful of with hotlink disable is that you don't hotlink disable the search engines and their image searches. Although it would depend on if you want those indexed I guess.

To optimize in Photoshop, always use Save for Web rather than Save. This will bring the size down without affecting the quality too much (sometimes not at all). In Save for Web, you can set how much optimization you want.