This bash completion looks at the last few commits and allows you to tab complete the commit id. No more typing git push origin somecommit:master

.git_push_bash_completion

function pushCommit() {
    git push origin $1:master;
}
function _pushCommit() {
    local RECENT_COMMITS=`git log --pretty=oneline master..HEAD`

    COMPREPLY=()
    local cur
    cur=$(_get_cword)

    local OLDIFS="$IFS"
    local IFS=$'\n'
    COMPREPLY=( $( compgen -W "$RECENT_COMMITS" -- "$cur" ) )
    IFS="$OLDIFS"
    if [[ ${#COMPREPLY[*]} -eq 1 ]]; then #Only one completion
        COMPREPLY=( ${COMPREPLY[0]%% *} ) #Remove ' ' and everything after
    fi
    return 0
}
complete -F _pushCommit pushCommit