Nice changing prompt character, based on the current repository type.

prompt_char.sh

function prompt_char {
    if [[ -d './.svn/' ]]; then echo '§' && return; fi
       # it's faster to test for a `./.svn` directory than 
       # to exec `svn` & check return codes

    git branch >/dev/null 2>&1 && echo '±' && return
    hg  root   >/dev/null 2>&1 && echo '☿' && return
       # redirect output of commands to /dev/null & 
       # echo custom char based on successful execution
    echo '○' 
       # Fallback to default
}