In the life of every device, there's a moment when you start to wonder whether it's still useful. Everything becomes old, and obsolescence is all but assured in the world of technology. But "old" is not the same as "obsolete."It's been more than three years since Apple debuted the original 9.7-in. iPad, the first tablet to go mainstream and the one that opened the floodgates to all the tablets that have followed. Then in March 2011, Apple discontinued the iPad, replacing it with the thinner, faster iPad 2 -- the same model that Apple still sells for $399.An original iPad (top) is bigger, heavier and slower than the iPad Air -- and is still great to have around the house.W
