Coming from the mighty Fireworks, I'm used to exporting PNG-8 files with alpha transparency - for many graphics, it's PNG24 quality using less bytes.
But I can't see how to do this in Illustrator. There's only a checkbox for Transparency, not the None/Index/Alpha options present in Fireworks. See below:
Is it possible to export a PNG-8 with alpha transparency from Illustrator, or can only Fireworks do this?
Go to File -> Save For Web.
A dialog box will appear displaying the original artwork on one side and what will be saved out on the other (a preview). On the far right are the settings.
In these settings, select PNG-8 from the format dropdown and configure the PNG-8 settings to your liking (transparency, color table, matte color, color reduction algorithm, etc.)
Then click save and you'll have exported a PNG-8 version of your artwork. PNG-8 only allows for 255 colors though (including transparency) so plan your artwork accordingly.