Mike Lee has to have the award for the most creative and obsessive XO laptop accessory compiler. His OLPC Flickr photo tag is the best way I've found to keep up with all the cool toys you can add to your XO.
Mike's fun find this week is a Lightwedge Mr Brightside USB Light in what should be called "OLPC Green". As you can see here, its a perfect addition to any XO laptop user who finds herself typing at night instead of in daylight.
Previously Mike found a hack that mixed a USB drive with the XO viewfinder, that while not for sale, is a cool dual-use device sure to start coffee shop conversations.
Note that Fuji claims its using "wasabi green". Whatever - we know the right name for that color.