Phase Change Memory (PCM) is fast, can be erased millions of times, should be inexpensive, and can shrink below 45 nanometers. In theory, it will compete with flash memory and drive prices down:

After 38 years, a new type of memory to hit market

Here’s how it works:

In phase change memory chips, a microscopic bit on a substrate gets heated up to between 150 degrees and 600 degrees Celsius. The substrate is made of the same stuff as CD disks. The heat melts the bit, which when cooled solidifies into one of two crystalline structures, depending on how fast the cooling takes place. The two different crystalline structures exhibit different levels of resistance to electrical current, and those levels of resistance in turn are then as ones or zeros by a computer. Data is born.

This video shows a typical memory cell:

[[[See previous invention]