The PlayStation 3 is seriously boosting its number of high-def movies available to download not only for rental but now also for purchase. The move comes after Sony struck a deal for the content with all of the major studios -- Warner,

Universal, Disney, Sony, Paramount and Fox -- making the PlayStation Network the first to do so. That's the good news.

The bad news is that most high-def movies cost $18 to $20 to download for purchase from the PlayStation Network. (Rentals, which are simply downloads with expiration dates, go for about $5.) That's too high. Why would I download, say, The 40-Year-Old Virgin for up to $20 to own when I can buy the Blu-ray from Amazon for $13? That price might be more palatable for movies not available on Blu-ray or new releases, but even the latter can be had in that price range during sales. Convenience is the prime attraction here.

No matter the price, if you're going to start downloading high-def movies with abandon, you're going to need more storage capacity on your PS3. Fortunately, there are detailed instructions online for how to add an external hard drive and how to upgrade the internal hard drive of a PS3.

By the way, the PS3 soon will get more features to boost its status as a home-theater control center. A kit to turn the system into a DVR has just been introduced in Japan, and a firmware upgrade to turn the console into a 3-D Blu-ray player is expected in the summer.