The basic old-fashioned way of putting it into boiling water and timing it so that you get the egg the way YOU like it is of course cheap, efficient and requires you to spend a little time until you get it right.
But there are two other methods I have found are QUITE successful and relatively automatic.
One is to use an "egg coddler" - although again you have to learn exactly how long it sits in the boiling water to produce the perfect egg for you, it is tidy and even permits you to include some tasty spices, bits of bacon or sausage, cheese or croutons. The egg coddler is a porcelain cup with a screw top - they are docorative as well as functional. Of course, in this case your egg exits the coddler sans shell - but it is of course already firm and you can put it into a little bag or plastic holder if you wish to have it later.
The perfect boiled egg in the shell comes out of the wonderful "egg muffin toaster."
I love this invention. I bought it last year INSTEAD of an egg coddler - they cost about the same - and by Christmas had given 4 to my kids and friends. It will toast your English muffin, sliced croissant, bagel or bread, heat up some pre-cooked meat such as bacon or sausage, AND cook your eggs so that all is ready to eat at the same time - in about 4 minutes! I turn mine on, then go shower, and when I'm done it's breakfast time!
The toaster uses steam to cook eggs and heat the meat. You can either cook a scrambled or poached egg, or make up to 4 boiled eggs. You simply vary the amount of water - there's a nifty measuring cop with a shell-piercer on the bottom so that eggs in the shell don't blow up! - according to the number of eggs and the degree of doneness. The manual gives cooking times and amount of water. I prefer using distilled or filtered water to avoid getting a bit of scum buildup in the heating basin of the toaster.
Using this device IS in a sense having a self-timing egg!