From the Memory Medallion website, this is how they're described:
The Memory Medallion is a small disc, about the size of a half dollar, which is embedded in a monument, memorial or grave marker. Inside the Medallion is a digital memory device that holds a photograph and life story of your loved one.
To access the information on a Memory Medallion, all you need is a handheld computer or laptop—and the special Memory Medallion “touch wand”. Simply connect the wand's cord to your computer and touch the metal tip to the Medallion. Instantly, the information on the digital memory device will download to your screen—and you'll be looking into a beloved face, or reading the life story of someone special.
The Memory Medallion can store one photograph and up to 600 words. Each profile page also offers hyperlink capabilities so you can access Internet sites, including genealogical sites, family history pages, military history pages and personal Web sites. The Memory Medallion opens up a whole world of photos, video and stories to enhance and enrich your memories.
With the Memory Medallion, the true spirit and meaning of a person's life can be stored—and shared—for generations.