when I download limewire's free application (version 2.5), i get an icon on my desktop with an upsidedown pentagram that's called limewiremac.bin. clicking it runs a program called hex edit, which doesn't appear to do anything lime wire-ish. is my lime wire application somewhere else? am i downloading anything functional at all? why the hell does it have an upside down pentagram on it? will it make me a satanist? help!

Rebuild the desktop (command-option at startup until dialog).
If that doesn't help, try using a different browser to download and make sure your are getting the installer from www.limewire.com.

What you are getting is a file in binhex encoded format which is unencoded using stuffit. Just drop the file onto the stuffit icon or launch stuffit and navigate to the file then choose expand and it will expand to a .sit file and then probably further to the Limewire installer folder. Double clicking on binhex files usually launches whatever texteditor application you have on your computer such as hexedit or bbedit.