With Locale and the HTTP Request Plug-in, your phone can post a http request to any Server available to your phone.
You could update your status online, control your home entertainment system, log into a Wifi at Work.
This is a plug-in: it requires "Locale" from the Android Market. You can not start it without Locale.
As also found in the official Google Android Market:
This application is a call minutes, sms, mms and data usage meter to monitor your credit usage. Never exceed your quota again!
Supporters unlock: free times/contacts/groups; widget; usage log; greater configuration of plan inclusions + more. A free 5 day trial is offered.
Please report bugs!
Please visit http://creditusage.matthewwardrop.info for more information.