If you're an Apple fan and you've owned several Macs over the years, but can't quite remember what specs that Power Mac G4 Cube had, or whether the late-2006 MacBook Pro came with a Core 2 Duo or the previous generation Core Duo? You need Mactracker.
The ultimate in Apple product reference, Mactracker, which is also available for iOS, is a searchable database of specifications, prices, configurations, names and OS versions that covers everything Apple since the Macintosh XL from 1983. You've got all the Apple desktops, laptops, servers and OS iterations from System Software 2.0.1 to OS X, each with detailed entries recording their introduction, history and specifications. Each device has an icon showing you want they looked like too, just incase you've never seen one.
Mactracker doesn't stop there though, all the hardware Apple has ever created is listed, from the humble iPod to cameras, scanners, mice, keyboards and more are listed. Want to know the dimensions of the Apple MessagePad 110? Or how long the Apple Color OneScanner 600/27 took to scan a page? Mactracker has you covered (that's 20 seconds per scan for those who are interested).
You can browse listings by device, model and age, or using a timeline from 1983 through till the present. If you're looking for a particular strata of devices you can use Smart Categories using search terms like all models with a G5 processor. You can also set up a list of all the models you own or have owned, helping you keep track of AppleCare, serials, purchase dates and networks.
Mactracker is available for free from the Mac App Store and is a must have for any Mac fan.