JZipMan is software that will allow you to manage archives on your Motorola ROKR E2.
1) Copy the .jar and .jad file on your memory card
2) Go to the file manager, start the .jad file and install the application on your memory card
3) Go to /.system/java/DownloadApps/ folder on the flash card. You will see folders with names like MIDletxxxxx. In one of them you will find the JZipMan.jar
4) In that folder find the file registry.txt. Open it with notepad and change the line "Domain: Untrusted" to "Domain: Trusted Third Party" (there will be security warnings) or to "Domain: Operator" (there will not be any security warnings)
5) Go the phone, select the application and give all rights in the application settings
6) Use the program and enjoy
Note: If you install the application on the phone memory - the procedure is the same, but the location where the files are stored is /system/ezxlocal/.system/java/DownloadApps