Need notification sent from arduino to phone

Hello,
I am new here, so hello!!
I am doing a project for school and am having difficulty finding a solution to one aspect. My project is an arduino Mega2560 based fire sprinkler system that continuously monitors a temperature sensor. If the temp reaches the triggerTemp, then the system is activated and turns on a water pump that feeds a sprinkler. The arduino also shows all the status of the system on an LCD screen, along with other minor things.
What I cant get to work is the ability to send a notification of ANY kind to my phone or email once the system has been activated to notify the use that the system is active. I need this to be wireless, so I have the Arduino brand WiFi shield, Arduino Wi-Fi Shield - DEV-11287 - SparkFun Electronics, but can not find a way to send the notification. I tried Ardumote, but apparently the wifi library and shield do not support UDP at this time. I tried twitter, but there is not a solution for doing this with Wifi instead of ethernet. I just need some form of notification to be sent to the phone, does anyone know how I can accomplish this? I can connect to the network fine, i just do not know how to configure a notification after that.
If I need to use some other form of shield or hardware to accomplish this that is fine, I just need this to work.

Two Questions:
What type of phone are you trying to notify? And do you have access to a WebServer with mail() and PHP?

I can think of two ways to do this... one of which is specific to iOS or Android, the other of which isn't.

Hi,
I am hoping and prefer to use this with my iPhone, but if needed I can use partners android. I don't have my own web server, so only standard public access to that. I set up the arduino as a local web server to see the temperature, but was not able to access that wirelessly, not sure why.
I am not very good at web based or network based solutions, sorry. I am a circuit guy. Anyway, since this project is presented at my school in the classroom I do not have the option of using Ethernet which seems to be the more easily done option. I really just need some kind of notification sent from the arduino to say "Hey, your sprinkler is going off!" I am not going to be picky on how that is achieved.
Thank you for your response.

If you get this to work with the " standard" Ethernet shield, then you can simply connect a little pocket router like this

To the Ethernet shield. That way you can use UDP through the Ethernet shield and use Ardumote on the iPhone. You can connect to the little router with your iPhone directly by running the router in AP mode.

That makes sense, and I am in need of a solution soon. It does raise the price of my project a bit, but who cares at this point. Thank you and I will look into this more. You have NO idea how good it is to have an idea of a solution, thanks. I never even came close to thinking of the pocket router idea.

You're welcome. BTW I can guarantee you that I know how it feels to finally have an idea for a solution.

My LED lighting system ( trippylighting.com) was min dire need of a remote control solution. I hade something working with a WiShield and Ardumote but ran against several obstacles that prevented me from developing the solution any further.
Then the Arduino WiFi shield was announced but did not happen for over a A year. It took half a year for to come across a video on YouTube showcasing exactly this router solution and I slapped myself of the forehead having missed this obvious solution. My system now is remotely controlled using TouchOSC from my iPhone. Smooth!

https://pushover.net is an easy one that ive used with scripts before, and should work for the arduino.

otherwise, you could simply pass url variables to a php script that mails to your phone. most phone carriers (if not all) have an email to txt message gateway.