RAR is a powerful command line-based RAR archiver for Macs. However, the lack of graphical user interface means its out of bounds for many users scared by anything technical.
RarMe aims to solve this problem by adding a GUI to RAR. RarMe is an AppleScript Studio application that uses RAR to create RAR archives. Note that in order to use RarMe you must download and install RAR first. This is because the RAR license prohibits such distribution of RAR without the author's written permission. RarMe is still very much a work in progress and many features of RAR are still not supported by it. For example, it does not yet check your input before attempting to create an archive, and errors are very common.
However, it's a darn sight easier that using RAR. To use it, you need to extract the RAR folder and locate the UNIX executable 'RAR'. Then place RarMe in the directory you wish to install it into. Right click on RarMe and choose 'Show Package Contents'. Double click on the 'Contents' folder. Finally drag the RAR application into the 'Resources' folder and you should be able to use RarMe.
RarMe isn't a fully functional solution to RAR's lack of a GUI but if you can get through the installation procedure, it makes using RAR a lot easier.