Hamster Archiver is a free tool for compressing and decompressing files. It works with most major formats and is easy to use.
Simply drag and drop the file onto the Hamster Archiver interface and it automatically archives or unarchives the file into the format of your choice. Hamster Archiver works very quickly even though there's a "Turbo" function for even quicker archiving although it's not really necessary.
The developers claim that Hamster Archiver is the first such utility to "take full advantage of multi-core processors" when creating zip-archives which may explain it's speed. Hamster Archiver supports most major formats including ZIP, 7Z, GZIP and RAR.
Simple to use, fast and supporting many formats, Hamster Archiver is a solid file archiver for OS X.