tee

A simple version of Unix tee with timestamping.
Read input from standard input and write to both standard output and a file.
Usage:
some_command | tee [-a] [-t] outfile
-t
prepend a timestamp
-a
append to file
Limitations:
Supports only text files
only short lines
This has been compiled as a command utility on Windows. The timestamp facility can be useful if piping the output of a test script, and then using the timestamp to correlate events with syslog/event logs.

See here for source file.