Locate Your Unprotected Android Device.

If you lose your Android smartphone and didn't proactively install a security or remote locator app, you can still find your missing phone by following our handy guide.
If you lost your Android phone or tablet, and you don’t have a remote anti-theft or GPS location app installed? Don’t beat yourself up too badly, because a few tricks may still help you remotely locate or secure it.

How to locate:

• You can use Android apps that can be remotely installed and activated via the Android Market website, which can give you a second chance at finding your lost or stolen smartphone.
• Your Android device must be powered on and have either a data or Wi-Fi connection in order for this to work.
• If your device is turned off, you might still have a chance of locating it when someone turns it back on.

•  Remote-Control Your Device With AndroidLost 
• AndroidLost is a remote-control app for Android devices that can be used for a variety of remote functions (including playing a siren and locating your device on Google Maps) via text (SMS) commands or the AndroidLost website. 
• To get started with AndroidLost, you’ll need a computer (or perhaps another smartphone or tablet) that you can use to access the Internet and check email.
• If you can, you should also ask a friend with a mobile phone to help you send SMS commands to your lost or stolen smartphone.

• AndroidLost is still in beta, but it already offers a bunch of neat remote features including SMS and call-log retrieval, plus features for sending text messages from your phone, taking and receiving photos from the camera, displaying messages on the device etc.

• You can also check the status (battery level, IMEI, phone number, and so on) of your missing device and have it send an email alert if the SIM card is changed.
• AndroidLost can also remotely lock your device with a PIN or even wipe it and restore your phone or tablet to the factory default
• However, even without access to your smartphone or tablet you can erase the SD card to protect your data.

Steps to use AndroidLost App:

• Open the AndroidLost page in the Android Market using your internet browser.
• Click Install, and sign in with the same Google account you use on your missing Android device.
• Within seconds, the AndroidLost app should automatically install itself on your device.
• Note that before you can start issuing remote commands, the AndroidLost app needs to authenticate your device with Google's servers, which it should do automatically.

• To check if the app has registered your device, go to the AndroidLost website and sign in with the same Google account that you use on your device.
• From there, click the Controls or Settings pages.
• If the pages appear with remote-control options for your missing device, you’re good to go.
• If not, you need to keep checking by logging out and back in every 5 minutes or so.
• If time is of the essence, you can try to force registration by sending an SMS message that reads “androidlost register” to your device from someone else’s phone.
• If you're trying to remote-control an Android tablet, you can remotely install the AndroidLost Jumpstart app to expedite the device registration process.

 Once the app successfully verifies your device registration with Google, you’ll be able to access the Controls page for your missing device on the AndroidLost website, where you can remotely locate or lock down your lost smartphone.