The invention of lithium ion batteries was the key. The earliest rechargeables were made with lead -- hardly a prescription for portability. But because lithium is the lightest metal, lithium-based batteries can store more energy at a given weight than any other variety. Lighter batteries mean smaller, lighter devices; beginning in the 1990s, you could actually put a phone in your pocket.
Running time remains an ongoing challenge, but researchers have no shortage of solutions. In addition to improved lithium ion batteries that use nanotechnology, a number of battery alternatives are slowly coming to market, including ultracapacitors and fuel cells. In fact, pardon me for saying that battery technology is poised for its next big explosion -- and personal technology is sure to advance because of it.
Voice over IP (VoIP)
You've made a few Skype calls and you've looked into digital phone service from your broadband provider, but that's as close as you've gotten to VoIP technology. Or so you think. In truth, VoIP is revolutionizing the telecom industry, blurring the lines between voice calls and digital networks.
Those prepaid calling cards that offer rock-bottom international rates? VoIP makes them possible. Similarly, a growing number of businesses use VoIP behind the scenes to eliminate long-distance charges between branch offices.
Routing calls over the Internet circumvents traditional telephone company charges, and fewer fees and taxes mean lower prices. Digital calls are easier to direct and manage, which makes them attractive even to traditional telephone companies. Don't be surprised if soon the landline you've lived with forever is replaced by an all-digital alternative--though you'll likely be none the wiser.
Thought your fancy video card was only good for gaming? Think again. Its graphics processing unit (GPU) is really like a second, highly specialized CPU. When it comes to certain kinds of complex math, its performance puts your desktop CPU to shame.
Until recently, all that power went to waste when you weren't chalking up frags. But computer scientists are finding novel ways to use GPU acceleration to speed up applications off-screen, as well. For example, a Stanford University project -- which uses many PCs around the world acting together as a supercomputer to assist protein folding-related disease research -- can offload calculations to the GPU to multiply its performance many times.