I have downloaded a song, put it in the playlist, and saved it in a folder. Now can I only listen to it in Limewire program, or can I listen to it in any other program? Any input will be appreciated!
Thanx.

Well,
You can listen it with any other program.
All files you downloaded with LimeWire is stored in
a folder called downloads by default.
To check the path of it go to "Tools" -> "Options" -> "Saving"
Open that folder with you explorer and doubleclick on it.
If you have an audio player it will open that song automatically.