The thin skin of firm tomatoes, peaches, plums, etc. can be easily peeled with the following method:
Place a pot large enough to accommodate 5 or 6 pieces of fruit on to boil.
While waiting for the water to boil, gently cut or score an 'x' through only the skin at the bottom of the fruit.
Once the water reaches a boil, carefully add the fruit, wait a few seconds, then remove the fruit. Do not allow the fruit to cook in the boiling water.
This method of blanching causes the skin to slightly blister, allowing it to easily peel from the flesh.
Transfer the fruit to a colander or drain basket.
Cool slightly to peel. The peel should easily slip off from the flesh.