CEBU, Philippines - Preserving your artifacts is a fun way to celebrate your family now and later - just don't bury the collection. "When it's unearthed, if ever, it's usually a soggy mess," says Paul Stephen Hudson, a cofounder of the Atlanta-based International Time Capsule Society. Pile everything into an archival box, then stow it away in a cool, dark place. Include the big stuff (artwork, school reports, notes to your future selves) and the little (movie stubs, a printout of a Facebook page, a toy with its batteries removed so they don't corrode). Items that won't stand the test of time: delicate clothing, food, or tapes and discs that will be outdated by technology. Add a silica-gel pack (which comes with new shoes) to absorb moisture, and set a date for the big reveal in 25 years.
(SOURCE: http://www.realsimple.com/work-life/family/family-activities-00100000086128/html)