Par-N-Rar is a graphical utility which accepts a directory as input and will repair/verify any PAR/PAR2/SFV/MD5 files in that directory. Once it verifies a set of files, it will attempt to unRAR them. Once it finishes unRARing a RAR archive, it will (optionally) remove the original PAR/RAR files.
Par-N-Rar is open source and is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See theGNU General Public License for more details.
Par-N-Rar v1.3 ( README ) (source)
Par-N-Rar v1.24 Par-N-Rar v1.23.3 Par-N-Rar v1.22.2 Par-N-Rar v1.21 Par-N-Rar v1.20.3 Par-N-Rar v1.15 Par-N-Rar v1.14
If you have any bugs or feature suggestions, drop me a line.