I hate sand / sleep in my eyes when I wake up. For some reason I only get it on a saturday or sunday morning. Nanobots which live in your pillow could come out and eat the sleep as it is exuded. They could then return to the pillow and deposit the sleep in a holding / evaporation tank slung under the bed. Once a year a pound of solid sleep could be easily disposed of in a single block. Could potentially open up possible uses for bulk sleep - as a foodstuff for fish, or in the pharmaceutical industry. Who knows, the cure to insomnia may lie in this stuff.