I'd add: whatever happened to microscopes? I loved getting one of those and a box of slides: bugs, plants, cells, all kinds of cross sections... And what happened to the 160 in one electronics kits from Radio Shack, ala http://www.radioshackcatalogs.com/html/1987/h104.html? (Actually, those last evolved into the rather clever SnapCircuits which are pretty fun, sold in Radio Shack and other fine stores).
