untested, cron script for reading in csv and making screenshots.

gistfile1.py

#!/usr/bin/python
import csv
from hashlib import md5

from selenium import webdriver

with open("/path/to/csvfile") as csv_in:
  browser = webdriver.Firefox()
  data = csv.reader(csv_in)
  for url in data:
    browser.get(url)
    browser.save_screenshot("/tmp/screen-cache/"+md5(data).hexdigest()+'.png')
  browser.quit()