I don't know how long you have to boil an egg to make it soft or hard or somewhere in between, only that if I forget I'm boiling eggs long enough that the pot is dry of water when I get back to the kitchen, then the eggs are probably very well cooked and likely to be inedible. No, it's never occurred to me to use an egg timer, even though I like my eggs soft-boiled and am really pickly about the degree of softness when I order at a restaurant.

I love these egg boilers by Eiko enough to motivate me to learn the nuances of egg boiling (please, no snide comments about how painfully easy it is) so that I can make my eggs soft and my daughter's eggs hard but not rubbery. You hang these boilers on the side of the pot, remember which color belongs to which egg eater, and then take each out according to your carefully monitored boiling times (the handles remain cool, so you won't burn yourself). And, the egg boilers also serve as egg cups, which is very nice for my tiny kitchen where there's no space for separate boilers and cups.

A set of 4 sells for $19 at Vessel (matching spoons are another $6). Also available in a transparent version (for monotone families whose members all like their eggs cooked the same way).

Via Kitchen Contraptions.