Archives your stuff from Instapaper. This saves the archive as a mobi file, but you can change that by replacing the last URL.

archive_instapaper.py

import urllib, urllib2
import cookielib

def getInstapaperArchive(username, password):
	
	login_url = "http://www.instapaper.com/user/login"
	home_url = "http://www.instapaper.com/u"
	kindle_url = "http://www.instapaper.com/mobi"
	
	params = {"username":username, "password":password}
	post_data = urllib.urlencode(params)
	
	redirect_handler = urllib2.HTTPRedirectHandler()
	cookiejar = cookielib.CookieJar()
	opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookiejar), redirect_handler)
	
	login_response = opener.open(login_url, post_data)
	home_response = opener.open(home_url)
	kindle_response = opener.open(kindle_url)

	return kindle_response
	

if __name__ == '__main__':
	from datetime import date
	save_file = '/your/save/dir/Instapaper_%s.mobi' % str(date.today())
	f = file(save_file, 'w')
	data = getInstapaperArchive("your@email.com", "instapaperpassword")
	f.write(data.read())
	f.close()