I like scanning at 300 dpi, and saving uncompressed bmp. It takes a meg per chip, but I have a 100 Gig hard drive and a 250 Gig external backup drive. I can always zip them, but I don't want to use lossy compression on my masters.

I know people who believe a camera gives you better detail and shadow. I haven't been able to get good results. The flash can cause problems with shiny chips straight-on. And on a scanner, dots per inch is a true measure of the size of the chip. It translates to true size on the printed page.

For the web, I save at 150 dpi jpg, with a medium compression.