You might remember mention of a new AT&T service called Toggle last month, a service which promised to allow enterprise users to access corporate email, calendars and contacts securely from whatever Android device they choose to purchase, while separately maintaining their personal data. AT&T's official Toggle app hit the Android Market today, heralding the beginning of the service, and bringing hugely useful functionality to enterprise users concerned with keeping their business and personal activities separate.

AT&T Toggle essentially allows users to operate in two different modes on a single device: a personal mode, which acts just like your stock device, and a business mode, which allows access to corporate email, calendars etc.

What's great about this app is that the resources in business mode can be looked after by IT administrators, meaning you don't have to worry about adding, removing, or updating apps, and you won't have to manage corporate data yourself.

Evidently, AT&T will be selling the system to enterprises, and will allow the service to be used on devices sold by other carriers, meaning the innovative split-mode functionality can be utilized by just about anyone using an Android 2.2+ phone.

Enterproid, the company behind Toggle (and funded by Google, Qualcomm and Comcast), has indicated that they are also working on bringing the service to iOS, and potentially other platforms as well.

Of course, your company needs to have authorized and implemented the service before you can make use of the phone-side client, but Toggle seems like a promising solution for business users who want to make full use of their personal device, while still having access to corporate resources.