Ever since the iPhone 3.0 came out with push notifications, I've been thinking what a good idea it would be to create an app that you could send your own custom notifications to and have them show up on your phone. It would have no purpose other than to open up an avenue for notifications which a program would send to them and they would send to that app.
I ran across Prowl a few days ago and found that Prowl does precisely that. Download it from the iPhone app store and register on their site. You will receive an api key which is used to identify you in any notifications sent.
Notifications can be sent from virtually any computer. Prowl is meant to work hand in hand with Mac's Growl program, but there are APIs available for Perl, PHP, Python, Ruby, Java and Lasso, as well as various web services and plugins which have been written to perform a certain task, such as watch Gmail and send notifications instantly when you get new mail.
There is already a python script and jabber bot available to push Gmail to your iPhone as well as scripts for Google Voice, Twitter, mIRC, Skype and others. The uses are endless.
You can also simply use curl to post to a special address like so:
curl https://prowl.weks.net/publicapi/add -F apikey=XXX -F application="My Notification" -F event="Testing" -F description="This is a test using curl to send a notification"
Within a couple of seconds, this will pop up on your iPhone
Clicking "View" or opening the Prowl app will show the notification, which you can delete, leave alone, or copy. It can handle some long notifications. I believe the limit is 10000 bytes. Here is a screenshot after I sent the curl command above twice in a row.
Prowl works great for anything you would normally email or text to your phone. I've only had it for a day and so far I have it set to send the weather forecast from weather.gov twice a day, sent a notification if the IP address on my home PC changes, notify me of precipitation moving into my area used in conjunction my earlier script.
I've been using the Gmail python script and it pushes mail within a couple of seconds of it being sent. When I send it from gmail.com, I get the push on my phone before the gmail page reloads.
By far, this is one of the most useful apps in the app store.
iPhone and Linux