The new api's have now been formally documented and released and allow you to modify the number of an sms contact remotely and stop/start a monitor remotely.
If you use an on call rota and frequently need to change the sms contact you can now do it via a simple link on a web page or in a script hosted on your server without having to logon to the control panel.
Similarly if you have a backup or housekeeping job and want to stop a monitor whilst it runs and restart it afterwards you can now do this remotely. When you stop the monitor you can optionally specify how long it should be suspended for and it will automatically restart after the period specified.
The new API's are documented in the documentation section of the control panel.