Key rings were invented in 1922 by a man called G Herluf Johnson, the actual ring part was invented by a juggler from Russia in the 1830's.
In the 1950s and 1960s with the improvement of plastic manufacturing techniques, promotional items including keychains became more unique.
visit http://www.justkeyrings.co.uk for more info and for some classic keyring shapes and designs.
Keychains can be made of a lot of things. Often they are made of metal and plastic, but sometimes cloth or other things are used as well. I have a keychain made out of an old motherboard. You can make keychains out of almost anything.
OSX keeps passwords in a "keychain" accessed by an application called, you guessed it, "Keychain Access". The password you set up when you first create a user account is the default password that encrypts the data and opens the file initially. You can change it to something else, however should you forget the new Keychain password you may lose whatever is kept within that file. 

Theoretically, if you forget your keychain password, you can reset it to your user password. To do this, you go to your Utilities/Applications File and select "Keychain Access." Choose the Keychain First Aid utility and click "Repair." It will ask for your username and password, and will tell you if any problems are found. You can try to have it reset the password to your user password. That allows you to access your keychain but doesn't change any of the passwords or encryptions in it. Unfortunately, that doesn't always work if the keychain password is different from your user password. When it doesn't, the only thing you can do is start over by deleting the old and creating a new keychain.
keychain
Keychain - 2012 was released on: USA: 21 July 2012
Yes. The compound word is a combination representing the specific item, a keychain.
The first year the Yamaha Warrior was made was 1987.
It was first made in the 1700s
What year was the first ever stove made??? the first stove was made in 1936 on June 30th!!
The first corvette was made by Harley Earl in 1927 The first production year was 1953
The first year for the GTO was 1964.
the first Chevrolet was made in 1911
The first watch was made in1965