How fast does an sr-71 blackbird go?

They don't go anywhere, they are no longer in use by the Air Force.

What a goofy answer...

An SR 71 Blackbird can travel over Mach 3 (3 times the speed of sound). Mach speed varies a bit by air density but it is roughly 742mph. This means that at Mach 3 the Blackbird is traveling at about 2225mph. This is literally faster than some bullet speeds (30.06 for example), and is faster than the earth's rotation (you could leave New York and fly to Hawaii and get there earlier than you left New York).