There is no other sound quite like it. No matter where you may be in the house, the harsh BANG! of a toilet seat slamming down on the toilet bowl will inevitably make you jump out of your skin. If you have kids, that jump is followed by a pregnant pause and a quick prayer that no fingers (or anything else, for that matter) were caught in between. Since potty training is difficult enough, removing this potential hazard is well worth the effort. Luckily, the solution is almost effortless.
I learned about soft-close toilet seats when I was building my house four years ago and was immediately sold. The seat and lid close smoothly and come to rest with the gentlest 'click' you can imagine. No more teeth-rattling slams and no possibility of a pinched appendage. It may very well be the best $60 I ever spent (and they are even less expensive now). The only downside is it's easy to forget yourself when you use a traditional toilet seat at a friend's house. BANG! Oops--sorry.
Replacing a toilet seat is simple, usually requiring nothing more than a screwdriver and ten minutes of your time. There are many soft-close seats out there so finding one to fit your toilet should be no problem. Most of the major plumbing fixture manufacturers carry them, including Toto, American Standard and Kohler.
(Image by Toto)

Shaw's Original Fir...
We bought new dual flush toilets for each of our bathrooms, and they happened to come with these seats. They're fantastic! Except for the fact that we still have one bathroom left to renovate. We're so used to just gently tapping the toilet seat and letting it do its thing, that we forget about that one ugly bathroom. Every few days somebody forgets about the crappy old toilet seat and you hear a WACK echoing through the house. We really need to finish that bathroom, haha.
Effortless except for $60 :). Cool invention, no doubt, but I was hoping for some free rigged-up trick!
@puella, I bet some intrepid mind over at Instructables could figure something out. Me? Not so much. Plus, they are more in the $40 range these days, I installed mine when they were fairly new on the market in the US.
Ha! Yes, I was going to say that it's easy to realize you're spoiled with the no-slam toilets when you use a traditional. That happens to my husband and I all the time, now that we're used to the one we have at home.
Richard--I'm sorry--I didn't mean to sound snarky! Obviously $60, or $40, means something different to everyone. I'm sure the convenience is worth the money to some. And I agree that the slamming toilet seat is a horrendous sound :).
We were forced to buy a Toto toilet when we realized too late (i.e. after the new floors were in) that the rough-in for our toilet was not the standard 12"... it hurt to cough up so much money for a toilet but every day we marvel at its brilliance, and my husband LOVES that the soft-close seat doesn't wake him up at night every single time his pregnant wife has to pee.
We recently replaced our cheap, scratched up toilet seat with a soft-close seat and it's awesome! But it also has the super-cool feature of a built-in (but removable) child's toilet seat that's magnetically attached to the top of the lid. It goes up when the lid does so it's never in the way, and the child seat pops down easily when you do want it. Then it all closes with a whisper. $40 and so worth it. BEST TOILET SEAT EVER.
http://www.homedepot.com/Bath-Toilets-Toilet-Seats-Bidets-Toilets-Toilet-Seats-Children-s-Toilet-Seats/h_d1/N-5yc1vZbza2/R-202721306/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053&superSkuId=202751305