Do you have a drawer full of old smartphones?
Phones that are perfectly usable but got replaced simply because you couldn’t resist the urge to upgrade to the latest and greatest?

I know I have. And you do too (don’t try to deny it – everyone does.)

This is a terrible waste of good technology. And there are lots of ways you can put these abandoned phones to good use, exploiting their excellent cameras and touchscreens. Here are a few:

Security camera
Why buy an expensive surveillance camera when you can use the one on your old smartphone? Just install a suitable app and you can keep an eye on your property from your current phone wherever you are.

A wide range of apps is available both for iOS and Android – take a look at the alfred.camera website (yes, that url is correct) for a free app that works on both.

All you have to do is install the app and sign in on both phones. Set the old phone as the camera and your current phone as the viewer, and the view from the camera is streamed to the viewer.

The motion detection feature triggers instant notifications to be sent to the viewer if movement in the field of view is detected. Two-way talk means you can speak to visitors, interact with pets or lecture burglars. It makes an excellent baby monitor, allowing you to make soothing noises as you sprint to the cot.

A low-light filter provides security even with the lights off.

You may need a tripod to hold the camera phone securely in position – take a look at the Joby Gorillapod, which has flexible arms that can be wrapped around posts or shelves to place the camera phone where it has the best view (around €30, FNAC)

Dash cam
Mount an old phone on your car’s windscreen or dashboard to record any incidents on your journey for which you may require legally-acceptable evidence.
Several apps are available, but one of the most highly-rated is Droid Dashcam from DroidCoolApps (available for Android on Google Play).

After installing the app, you will need to mount the phone on the windscreen with a suitable gizmo – take a look at the Belkin universal phone holder, which attaches to the windscreen with a suction cup and holds the phone firmly in a spring-loaded grip (€40, Worten). Don’t forget to plug in the USB charging cable as recording video takes a lot of power.

Video resolution, frames per second bitrate can all be easily adjusted to optimise the amount of data being stored in the phone’s memory. The system can be set to start recording automatically when the phone’s motion sensor is triggered.

Trackpad and keyboard
You can use your old phone as a wireless trackpad and keyboard for your computer. Why? Mostly idleness – it lets you play music or watch videos from the comfort of the sofa without having to get up to change tracks or whatever.

The software is at remotemous.net: just download and install the app, make sure the phone and the computer are on the same wifi network and click to connect. It’s as easy as that.

The phone screen will be transformed into a trackpad with left and right-click buttons, allowing you to move the cursor easily round the computer screen. You can also bring up an on-screen keyboard if you need to enter URLs and so forth.

The app is free but the pro version adds a whole lot of useful features.

Webcam
The videoconference facilities on the average laptop are notoriously rubbish, with very low quality cameras and microphones. Any TV newscast these days will feature at least one talking head that looks as though it was filmed in the 1950s in a snowstorm.

You can improve matters hugely by mounting your previous phone next to the laptop screen and using one of its cameras and its voice-optimised microphones instead.

Step 1 is to download an app for the phone and a client for the laptop. A good system called DroidCam X is available at dev47apps.com – it works on Android and Apple phones but sadly only on Windows or Linux computers.

The software enables you to watch the video on the laptop screen while filming you on the phone. The link can be via wifi or USB, but USB is preferable partly for an uninterruptible connection but also to prevent your phone’s batteries running out.

The free version of DroidCamX films at standard definition and has ads – the Pro version enables high definition, autofocus, zoom, rotate/flip/mirror and several other adjustments.

Step 2 is to attach the phone to the laptop screen. One Ten Design’s Mountie laptop clip holds any phone or tablet firmly in place, which is useful not only to use the phone as a webcam but also as an extended screen – see below (£22 at mobilefun.com.)

Extended computer screen
Why not use your old phone or laptop to make your computer screen bigger?
Mount the smartphone next to the computer screen, install a suitable app such as Spacedesk (spacedesk.net) and the phone’s screen will mirror the computer screen. Change to ‘extended screen’ and you can drag and drop stuff from your computer to your phone exactly as if the phone was part of the computer. It is even possible to add several phones and tablets to form a video wall – very cool.