My boyfriend loves crystal glassware. Unfortunately, he doesn't love the price tag it usually comes with. So every time I hit town, I stop by the thrift stores to see if they have any lovely pieces that I can take home.
You've probably encountered this: a beautiful bowl/vase/plate/cup at the thrift store, just waiting for you to buy it. Snatch it up, pay for it, trundle it home--only to find that the stupid little price sticker is practically cemented on. You pick at it, trying to remove the gunk, and then you end up with a little rectangle of gunk, and what's worse, it can't be washed off without scratching your find.
Vegetable oil is your friend in this case--"Fear not! You will never again have to live with a little black patch of sticker-gunk again!". A little dribble directly on top of the sticker, then rub it in with your fingers. Peel back an edge, and from then on the sticker should come off easily, though slowly.