Well, I actually made the solution.
I made a screenshot of the lime slice on this forum and used GraphicConverter to fix it up and make it transparent. I made it a TIFF file.
I tried to change the program icon by using copy and paste with "Get Info." But if didn't work. I guess LimeWire put a block on that.
But I hacked into the program.
Follow this steps:
Download the icon here. Just Control-Click:
http://home.earthlink.net/~jnrz0/LaunchAnywhere.icns
Then open your LimeWire folder, Control-Click the Limewire program.
Select "Show Package Content"
Open "Contents" folder, then "Resources" folder
Drag the file you just downloading into this folder.
It will say that you already have a file named this and if you wish to replace it. Say yes.
Now, log out of OS X and log back in. You should now have the icon.
Geez. All this for a freakin' icon!!?? Thanx LimeWire for all the work!