Put the kettle on. Put the tomatoes (without their stalks) in a deep bowl. When the kettle boils, pour the water over them. Scoop them out one at a time with a spoon and peel them as quickly as you can. If there are a great many to skin, do them in several batches, as standing in hot water makes them mushy.
If you only have one or two tomatoes to peel, and a gas cooker, stick them on a fork and hold them over a burner. Turn the flame up high and turn the tomato in it until the skin pops, singes and splits; it will then peel off quite easily.