Solution: Find the icon of StuffIt Expander and drag the file to it. It will unpack most anything, especially a .sit file, which StuffIt created. It will not mount disk images. Keep an alias of Expander on your desktop for convenience.

Remember, however, that .dmg files are only for OS X and will do you no good under 9.x. An .img file is a volume image that Disk Copy or Toast will mount. Send Sherlock to find Disk Copy. It is already on your Mac. This is a handy little application that, among other things, can split a disk image so that it can fit on diskettes or CD.

(You know you wouldn't have this problem if Apple were sending decent documentation with their computers like they used to...)

To avoid this problem in the future, for 9.x, check your File Exchange and Internet Control Panels and see if these suffixes are set for Expander or Disk Copy as necessary. Then they will arrive in Limewire with the proper creator and file type.