I find myself cutting lots of parallel slots (for shelf inserts, shelving, or racks) and now am staring at a series of projects with more parallel slots. Of course the distance between the slots (from 1 to 12 inches apart), the width of the slot (1/8" to 3/4"), and length are all different (4-36"). I'd like to get some ideas on how to build, plans to build, or where to buy (good but inexpensive) a jig to help with cutting them. Typically I use a router with a spiral bit or the table saw with a dado blade.