Yesterday, the USAF launched an experimental aircraft, the X-51A, and it achieved Mach 6 for more than 3 minutes. It used scram-jet technologies, a stepping stone towards space-planes.
Now there is still a long way to go. Mach 6 is fast, but three minuets is not very long and to reach orbital speeds you need something on the order of Mach 16 or 17. Still is is very cool that the USAF is still in the record busting business.