Those of you who download multimedia files may come across the UHARC compression format (filenames with .uha extension). The codec is available only for Windows, but you are still able to extract them under Linux. First, get Wine (instructions for that can be found elsewhere). Second, visit this link and extract the contents:
The file you want is UHARCD.EXE (note that UNUHARCD.EXE also works, but has less features).
The problem that frustrated me for the longest time is that I tried using UHARC.exe instead (notice this one doesn't have the "D" at the end -- you need the UHARCD file instead, because that one is made for Dos-mode. If you try using Wine with UHARC.EXE, extraction will appear to be underway, but will not actually work.)
Place the UHARCD executable in the same folder as the compressed file which you want to extract, then open up a terminal and navigate to that directory. Suppose your archive is named movie.uha and it's password protected, with the password "ihateapple", issue the following command:
wine uharcd e -pw_ihateapple movie.uha
For me, the progress indicator in the terminal remained at 0% the entire time, oddly enough. If that happens to you, check to see if the actual file is increasing in filesize. If it is, everything is going fine.