If I remember right, this came out of my old G4 Powerbook 12" after I upgraded. Was working fine when I took it out a few years ago, and stored in anti-static baggy ever since so should be working fine still.
Note that I think there are two sizes, one for laptops and one for desktops, this is for laptops. By today’s standards this is not a lot of memory for a computer. RAM, like this, helps your computer do more things at once. It does not make your computer faster, it just makes it be able to do a lot of thing at the same time a bit more efficiently.
See a few more pics on it’s Flickr set at http://www.flickr.com/photos/m4th/sets/72157623977195680/
(pics having trouble uploading on my current rubbish cafe connection, promise to upload soon!)