perl -MTime::HiRes=time -E"$|++;say scalar localtime while sleep 1" 
    | tee junk.log
Fri Feb  5 22:42:58 2010
Fri Feb  5 22:42:59 2010
Fri Feb  5 22:43:00 2010
Fri Feb  5 22:43:01 2010
Fri Feb  5 22:43:02 2010
...