def multicolumn(list, format, cols=4):
    """Format a list of items into a multi-column list."""
    result = ''
    rows = (len(list)+cols-1)//cols
    for col in range(cols):
        result = result + '<td width="%d%%" valign=top>' % (100//cols)
        for i in range(rows*col, rows*col+rows):
            if i < len(list):
                result = result + format(list[i]) + '<br>\n'
        result = result + '</td>'
    return '<table width="100%%" summary="list"><tr>%s</tr></table>' % result