import os, time, random, sys

class message(str):
    def __new__(cls, text, speed):
        self = super(message, cls).__new__(cls, text)
        self.speed = speed
        self.y = -1*len(text)
        self.x = random.randint(0, display().width)
        self.skip = 0
        return self

    def move(self):
        if self.speed > self.skip:
            self.skip += 1
        else:
            self.skip = 0
            self.y += 1

class display(list):
    def __init__(self):
        self.height, self.width = [int(x) for x in os.popen('stty size', 'r').read().split()]
        self[:] = [' ' for y in xrange(self.height) for x in xrange(self.width)]

    def set_vertical(self, x, y, string):
        string = string[::-1]
        if x < 0:
            x = 80 + x
        if x >= self.width:
            x = self.width-1
        if y < 0:
            string = string[abs(y):]
            y = 0
        if y + len(string) > self.height:
            string = string[0:self.height - y]
        if y >= self.height:
            return
        start = y*self.width+x
        length = self.width*(y+len(string))
        step = self.width

        self[start:length:step] = string

    def __str__(self):
        return ''.join(self)

i_message = raw_input("Input a message: ")
messages = [message(i_message, random.randint(1, 5))]
for t in xrange(1000):
    messages.append(message(i_message, random.randint(1, 5)))
    d = display()
    for text in messages:
        d.set_vertical(text.x, text.y, text)
        text.move()
    sys.stdout.write(str(d))
    sys.stdout.flush()
    del d
    time.sleep(0.1)

juan@maverick:~$ /usr/bin/env python matrix.py
Input a message: PYTHON