Nate Berkopec‘s article is chock full of useful information, but I was particularly taken by his framing of a developer’s job (emphasis his):
As developers, our job isn’t to tell the designers “Hey, you’re dumb for including over 500KB of WebFonts in your design!”. That’s not their job. As performance-minded web developers, our job is to deliver the designer’s vision in the most performant way possible.
The unicode-range property describes what characters the font supports. […] By telling the browser what characters the font supports, the browser can look at the page, note what characters the page uses, and then only download the fonts it needs to display the characters actually on the page.
Brilliant. I switched to serving fonts from Google and trimmed 45–70 kilobytes from my homepage. Your mileage may vary, but… not bad.