This is X11 centric but I mapped the largely useless context menu button to the compose key. where it actually gets used.

For those unfamiliar with the compose key it is a superior input mechanism for rare characters that maps a mnemonic sequence to the character in question. you want an ø type compose o /

A tutorial if you do not have a compose key configured, I tend to run a minimal bare bones X11 setup, A more full featured environment may have it's own way of doing it.

map the compose key in ~/.xsession

    xmodmap -e 'keysym Menu = Multi_key'

    include "%L" #include the compose file found in /usr/X11R6/share/X11/locale/<localemapping>/Compose
    <Multi_key> <w> <e> <b> : "" # spiderweb
    <Multi_key> <c> <c> <c> <p> : "\xe2\x98\xad" #symbol representing proletarian solidarity between agricultural and industrial workers

I don't know if the compose system is found any where else but I regard it as one of the better things to come out of the X11 project. A little below select / middle click paste.