Tested:
# fab -H server mktemp
# fab -H server mktemp:world_readable=True
# fab -H server mktemp:world_writeable=True
# fab -H server mktemp:world_readable=True,world_writeable=True
def mktemp(world_readable=False, world_writable=False):
    """
    Create a temporary directory.  Caller must delete after use.
    """
    print 'r='+world_readable
    print 'w='+world_writable
    public = world_readable or world_writable
    if public:
        temp_base = '/tmp/fabric/deploy'
    else:
        temp_base = '~/.fabric/deploy/tmp'

    unique_dir_name = hashlib.sha1("%f"%random.random()).hexdigest()

    temp_dir = temp_base+'/'+unique_dir_name

    if world_readable:
        if world_writable:
            mode='0777'
        else:
            mode='0755'
    else:
        if world_writable:
            mode='0733'
        else:
            mode='0700'

    mkdir(temp_dir, mode=mode)

    return temp_dir