importing a module given a path to the file

[Skaperen]

i want to have my script take a path to a file that it gets (may be typed in, or read from some other file, or given as a command argument) and import it as a module without any copying and/or renaming of files. i vaguely remember that i saw, a few years ago, a function that maybe could do this, but i cannot recall what it is or where i saw it, now that i need it. any ideas?