3G or the "3 Grand" Network, was invented in 1986 by Charles Kaplin as part of an Amateur Inventor Contest sponsored by Apple (the grand prize being of course, $3000.00). After winning the contest however, Charles Kaplin was sued by Apple claiming they owned the rights to his invention since they sponsored the contest. Kaplin won the case in federal court, and vowed NEVER to work with Apple again, adding a clause in his will which stated that his 3G technology should not be implemented in any Apple products under penalty of law. Charles Kaplin died in 1998 of complications from Small Pox, and to this day, 3G is not available for any Apple products. So unfortunately, you'll never see it on the iPhone.
To answer your second question, 3G speeds have been clocked at transferring data in 1/32 the speed of light, making it the data transferring network of choice for NASA (among countless others).