A script to enable walking lines to your vim

line_walker

python << EOF
import vim

def line_up():
    current_line_number = int(vim.eval('line(".")'))
    current_line = vim.current.line
    dest_line_number = current_line_number - 1

    if current_line_number != 1:
        vim.current.buffer.append(current_line, dest_line_number - 1)
        op = str(current_line_number + 1) + 'd'
        vim.command(op)
        vim.command(str(dest_line_number))

def line_down():
    current_line_number = int(vim.eval('line(".")'))
    current_line = vim.current.line
    dest_line_number = current_line_number + 1

    if current_line_number != len(vim.current.buffer):
        vim.current.buffer.append(current_line, dest_line_number)
        op = str(current_line_number) + 'd'
        vim.command(op)
        vim.command(str(dest_line_number))


vim.command('map <C-Up> :py line_up()<cr>')
vim.command('map <C-Down> :py line_down()<cr>')

EOF