THE COMICS v21 #1, the January, 2010 issue of Robin Snyder's monthly newsletter, features a cover drawn by Steve Ditko (adapting the lettering from the logo above, by Creig Flessel), celebrating the 20th anniversary of the publication launched in January 1990.
THE COMICS (originally ROBIN SNYDER'S HISTORY OF THE COMICS) has been one of the primary forums for Ditko's essays over that time, including "An Insider's Part Of Comic History - Jack Kirby's Spider-Man", "The Sore Spot Cause And Crusade", "The Stolen Art Page", "A Mini-History", "The Avenging Mind", "Toyland" and "The Ever Unwilling". It also saw a fair bit of Ditko's art, most notably the first printing of "Laszlo's Hammer" in 1992.
In addition to the Ditko, the newsletter has also printed extensive first person accounts of comic book history and unseen art and scripts from the likes of Robert Kanigher, Ric Estrada, Sheldon Mayer and dozens more.
Ordering info for the newsletter is on this page. Many, but not all, of Ditko's contributions to the first decade are included in the 2002 AVENGING WORLD collection (including "Laszlo's Hammer") and in STEVE DITKO'S 32-PAGE PACKAGE TSK! TSK! . Most of the later issues with Ditko work, including last I checked all 16 chapters of "A Mini-History", discussing the creation of the early Spider-Man comics, are still available directly from Snyder, contact him for availability and pricing.