YES, Limewire & Frostwire are portable straight from the box
Did you realize Limewire & Frostwire are portable straight from the box?
Just copy their installation folders to folders on your USB memory stick.
The only needs are the machine they're running on must have a resent version of JAVA installed.
Only a few minor issues
Start either from the .JAR file (frostwire.jar, limewire.rar.)
Both will have you go thru the options setup every time they are run.
Just be sure in both to point to a location on your stick to download to and goto options in both and have them shutdown immediately and not show a icon in the system tray.