I know Kevin Cornell from The Superest, a fantastic illustrator's one-upmanship he ran with Matthew Sutter (covered here and here previously on Neatorama).
Kevin has recently written a very neat post on his Bearskinrug blog about the actual implements used by professional illustrators - pencils, and pen and ink drawing tools. In the age of photoshop, it's quite refreshing to find that some people still draw the good ol' fashioned way!
Here's what he wrote about quill pen:
Here is my Crow Quill pen — a sludge-slickened Speedball #102. Two hundred years ago this would have been just one giant feather with the end split to hold ink. Goose feathers were the most common, but if you wanted really fine lines, you used a crow feather. During the eighteenth century, when wearing wigs and signing Declarations and Constitutions was all in vogue, we killed off all the agreeable crows, the kind that didn't mind just handing over all their feathers. This left us with only the angry kinds of crows, who steal our corn and hang out in murders. So today we manufacture our own pens. That's the price of freedom.