Since almost everyone has a mobile phone already, and SMS-based solution seemed appropriate. In order to implement this we need two things:

1. An SMS shortcode
2. A system to notify when the shortcode is triggered

It’s irritating and expensive to acquire your own shortcode, but there are several services that will allow you to use one in exchange for a small fee or advertisements in your messages. TextMarks is my favorite (I used TextMarks for my WhereAmI project). While TextMarks markets their service as a system for mobile mailing lists, they allow you to reserve a keyword and define a behavior (that can include pulling data from a URL!) to occur when that keyword is triggered.

Configuring TextMarks

Sign up for TextMarks and choose a keyword. Configure the keyword to respond with the “First 120 characters on web page”, and point it at the future home of your script (you can always come back and modify this later).

Note the \0 as the value of the msg parameter — this instructs TextMarks to send along any additional message contents as the value of that parameter. That means if someone were to text 41411 “doorbell hi this is hilary”, TextMarks would call the script with the param msg=hi this is hilary. This can be quite useful.

The Script

This script is written in Python, but you can use any scripting language you like. This particular script just sends an e-mail to an account when the ‘doorbell’ is rung, but you could have it do pretty much anything up to and including ringing a real bell (which may be coming soon!).

#!/usr/bin/env python
# encoding: utf-8
"""
doorbell.py
Created by Hilary Mason, feel free to use this code in your own projects.
"""
 
import sys, os
import smtplib
import cgi
import cgitb; cgitb.enable()
 
class Doorbell(object):
	GMAIL_USERNAME = 'YOURGMAILACCOUNT@gmail.com'
	GMAIL_PASSWORD = 'YOURPASSWORD'
 
	def __init__(self, msg):
		message = """\
From: YOURGMAILACCOUNT@gmail.com
To: YOURGMAILACCOUNT@gmail.com
Subject: KNOCK KNOCK, someone is at the door!
 
%s
		""" % msg
 
		server = smtplib.SMTP('smtp.gmail.com:587')
		server.ehlo()
		server.starttls()
		server.ehlo()
		server.login(self.GMAIL_USERNAME, self.GMAIL_PASSWORD)
		server.sendmail('YOURGMAILACCOUNT@gmail.com', ['YOURGMAILACCOUNT@gmail.com'], message)
		server.quit()
 
		print "You knocked! You can also call us at 347-586-9270. <3, NYC Resistor"
 
 
if __name__ == '__main__':
	print "Content-Type: text/plain\n\n"
 
	form = cgi.FieldStorage()
	if 'msg' in form:
		w = Doorbell(form['msg'].value)
	else:
		w = Doorbell('There is an anonymous monkey at the door.')

And that’s it! Provided you have your keyword configured to point at your script, and the script living at an accessible address, you’ll get an e-mail whenever your SMS doorbell is rung and the person who sent the message will get back a cute response confirming their action.

Finally…

This setup can be easily extended such that a message containing ‘doorbell hilary’ could e-mail only me, or be forwarded to my phone.

I’m curious to see if having a remotely accessible ‘doorbell’ will encourage pranksters — we might need to add a password.

Just text 41411 with whereami <username>, where <username> is a username that you or someone you know is likely to use.

For example, if you text whereami hmason to 41411, you’ll see a response much like the image to the left.

This app works on the principle that people tend to use the same username for many applications. The WHEREAMI script will search through a variety of web services for a result for that username. All of the information is public and available without logging in.

Right now, the script will search Brightkite, then Dopplr, and finally Twitter. If you know of another site with public user location information, please comment below and I’ll add it!

Open tab count extension in the status bar

How many tabs do you have open in your browser right now?

Did you have to count manually? Are you using Firefox? Try the open tab count extension!

I created this extension because I wanted to explore memory management in browser tabs, and I was curious about the Firefox extension architecture. I’m not quite as eager to explore memory hacks in Firefox now that Google Chrome is out and handles that issue natively, but I’m still using this extension to monitor my tab (over)usage.

The extension puts a small icon in the status bar alongside the number of open tabs. If more than one window is open, the extension shows the number of open tabs in the current window / the total number of open tabs.

Please let me know below if you have any comments!

Update: An update has been submitted to Mozilla that supports Firefox 3.5, and it’ll show up on the it’s now available on the official extension page once it’s been approved.