About piping linux program output

Does anyone know how I can let the output of a linux program go to stdout and also a file output at the same time? This is because I want to see the progress on stdout (takes hours to run it), but at the same time I want to log the output in a text file too.

>>9
outright refusal to flush stuff when you want it output means you're a CRAPPY LINUX PROGRAMMER, and any advice from EXPERT LINUX PROGRAMMERS would be wasted on you.

also, tee.