Another alternative is 'ts' which is part of joey hess's awesome collection of unix tools, moreutils.[1] I did not find out about ts until too late so I am still in the habit of using tai64n from djb's daemontools, which adds a tai64 timestamp to every file[2] and then tai64nlocal[3] in order to convert the timestamps to something useful to humans.
If you don't know about moreutils check out the collection. I don't know what I'd do without vipe or vidir:
Chronic: runs a command quietly unless it fails
combine: combine the lines in two files using boolean operations
ifdata: get network interface info without parsing ifconfi
ifne: run a program if the standard input is not empty
isutf8: check if a file or standard input is utf-8
lckdo: execute a program with a lock held
mispipe: pipe two commands, returning the exit status of
parallel: run multiple jobs at once
pee: tee standard input to pipes
sponge: soak up standard input and write to a file
ts: timestamp standard input
vidir: edit a directory in your text editor
vipe: insert a text editor into a pipe
zrun: automatically uncompress arguments to command