How many iPads has Apple sold?

Apple now says it's sold 450,000 iPad units, a monster jump from last week's declaration of 300,000 units sold on April 3, the tablet computer's first day of release.

According to Apple's Chief Executive Officer Steve Jobs, iPad users downloaded 250,000 iBook titles on the first day, with that total now above 600,000. Customers have also downloaded more than 3.5 million iPad apps from the Apple store, which now features 185,000 apps.

So many people have bought the iPad that Best Buy, Apple's only iPad channel in the U.S., has sold out of them until inventory can be restocked on April 11.

All this success can mean only one thing - competition. Other companies are stepping up efforts to put a tablet computer on the market by the end of 2010. Hewlett-Packard and Nokia are both working on tablets. HP says theirs will feature at least one camera and video-conferencing capability. There's no official details yet on Nokia's effort.

What will this mean for you? Hopefully, lower prices, a better machine with more capabilities and more applications you might find useful. Apple's iPad starts at $499.