Q2 2008: 1,703,000

Add up the quarterly numbers, and Apple sold just over 5.4 million iPhones in the handset's first year. (I also tried to get first-year numbers for the iPod, which launched in November 2001, but Apple's financial reports didn't break down iPod sales back then.)

If Lee's blog post is to be believed, Apple plans to sell nearly twice as many tablets as it did iPhones in the product's first year.

Call me a pessimist, but that's hard to believe. Remember, the iPhone was entering a well-established cell phone market when it debuted in 2007. People had used cell phones for years. They liked cell phones and understood their value. Apple's pitch back then: The iPhone is better than any other cell phone on the market. Millions of customers agreed, and the rest is history.

The tablet? Well, that's a much harder sell. The iSlate is sort of a big iPod, but not really. It performs a lot of notebook-like functions, but it's not really a notebook either.