1-26: 22 seconds
26-1: 17 seconds
a-z: 7 seconds
z-a: 16 seconds

I don't know why I was faster counting down than up. I think it's because I normally count seconds when counting up, so I tend to pace myself.

As for the alphabet... I didn't recite it -that- fast. When I try to recite it as fast as possible... 2 seconds. I will also admit to having practiced reciting the alphabet quickly, forwards and back, in my misspent youth (I coulda spent it playing sports, having sex, and getting drunk, but no, I spent it on programming, Rubiks cubes, and reciting the alphabet forwards and backwards. I now know the error of my ways...)

Timing done with "date;read;date" on a WinNT box running cygwin.