An excellent purveyor of the "small game" concept, Gamefix magazine, which later resurfaced as Competitive Edge after the publisher (One Small Step) recapitalized, publishes a playable, low-density, low-complexity game in each issue. I am an avid fan of this publication, and recommend you visit the OSS Website.
OSS Games, long thought moribund, is back in action. See their site for new online issues! OSS Rocks!
OSS has a very specific policy about pbem gaming utilities and their distribution online. Be sure to read this. NOTE that all file posted on this page are considered under license from OSS and I have their express permission to post them for non profit use.