Hewlett-Packard Laboratories has <A HREF="http://news.zdnet.com/2100-1040_22-6094586.html?tag=zdnn.alert">squeezed a computer onto a sticker.</A> Memory Spot, a technology devised by the research division of HP, is a self-contained storage device with a radio and processor that sticks to photos, documents or cards. About the same size as a shirt button but thinner, a Memory Spot can be stuck onto the corner of a family photo: Wave a reader over it, and the spot will serve a video or audio recording of the subject of the picture to a nearby computer or cell phone.