Stuffit should do it. You can get the free Stuffit Expander here. However, there was a time Stuffit would crash when I was using it to uncompress a large 1.2GB archive. That was when I discovered RAR Expander, which works way better and, best of all, is free.
wow u guys replied pretty fast. thanks byerly and elbert btw i was reading stuffit's specs and it says there it cant work with rar