Post-It notes . . . Band-Aids . . . sliced bread . . . . Bookmark this one under the “Why didn’t I think of that?” heading. Take a visit to Onesole.com and prepare to enter a shoe store unlike any you’ve seen. Onesoles are a unique concept in footwear. You choose among 12 different soles that can be worn with an endless variety of snap-on tops. Created by a woman who traveled extensively, Onesoles are proof positive that necessity is definitely the mother of invention. You can literally have a wardrobe full of shoes with only a couple of soles and a handful of tops. Soles vary from the flirty and dressy Kitten ($109.99), to the flip-flop-inspired Classic ($80). With 14 different types of tops, there is something for everybody. Solids (28 different colors), holiday motifs, patterns, collegiate logos, you name it. Onesoles even offer customized options: you can send them photos, design a monogram or mail them a swatch of a pattern you want to match. Each sole comes with one top and your choice of two more. Soles range from $80 to $129. Tops start at $13.99 and go up to $29.99 for more customized looks. Onesoles also make great gifts - after you’ve bought a set for yourself, pick up some for your shoe-obsessed girlfriends. They will love you for it.