Is there anything that you know of for OSX that can do a full image or the OS partition in the same effecient way that Ghost, Drive Image or Acronis do for PC?

So far the only thing I've ( and my mac friend ) have seen is SuperDuper
but I'm not convinced that this program really captures an "image" of the OS partition to a file.

Ideally, a restorable image "file" as opposed to an other bootable clone that uses a whole partition is what is needed.

Any ideas are very welcome. Possibly it's just not doable for MAC but knowing either way would be great.