UTilities by Rich Wynne provides some great utilites for Mac Unreal.
The one that catches my eye the most is UTCacheCleaner... Ever log into a server and have to wait for a 3meg map to download? Then, you can never choose to play that map again later? This utility will clear your cache and move those maps to the proper place.
They're free, so be sure to send Rich a thank-you email to show your support.