Companies such as Apple and Microsoft are barely middle aged by comparison, while Google and eBay are just children at this point. The question is whether any of these companies will reach the 100-year mark. Here is a look at five companies that could stand the test of time:

The company changed the way people buy books, practically driving Borders and Barnes and Noble out of business. Amazon.com sells a lot more than books today; last fall, it bought . It is hard to imagine that people will stop buying stuff, so Amazon.com should be a shoe in for reaching the big 1-0-0.

How many of us ever took part in an auction before eBay? While the company has slowly moved away from the small sellers and one-of-a-kind items, eBay still caters to its , many of whom use it as their primary source of income. eBay also owns PayPal, and while the company has faced a , this credit card pass-through is going to be hard to beat. Love it or hate it, PayPal remains the easiest way to send money online, and eBay will maintain that position for a long time--maybe even 100 years.