In with the new and out with the old, that’s the name of consumerism. If you’re keeping up with the latest trends of what tech has to offer, chances are you’re carrying the newest iPhone or fancy smartphone. That also means it’s pretty likely you’ll have one of its predecessors lying around in your bedroom drawer not knowing what to do with them.

Instead of cutting the cord and passing your old smartphone on to a friend or selling it off for petty cash at the month’s end, we’ve rounded up some ingenious life hacks that will help prolong the relationship with you and your devices.

Go full-on creep or paranoid

Use the camera to spy on people. No but seriously, iPhones especially are well-known for having pretty snazzy cameras so don’t let that feature go to waste. Set it up as a motion detector near your front door or as a nursery monitor. In most cases you’ll require an internet connection so remember to keep your device connected to a charger and Wi-Fi.

If you want to stream the feed to your computer, simply download VLC media player, go to “Media” then “Open Network Stream” and add your smartphone’s IP address given in the app.

Many of the apps out there require a monthly subscription with light charges. See free Android apps like Mobile Security Camera (FTP) and AtHome Camera or Baby Monitor 3G for iOS. If you have existing cameras and just need a remote monitor see IP Cam Remote with Audio and iTunes’ iCam.

Use it to help AIDS research and global warming

Yup, it doesn’t really matter how old, your smartphone is pretty damn powerful which means it can do some serious number crunching. The computer’s hardware can be used to help study diseases, predict global warming, or discover pulsars. You can decide where to contribute.

This ingenious app, called BOINC (Berkeley Open Infrastructure for Network Computing) boots up only when your smartphone or tablet is plugged into the charger and connected to Wi-Fi. It being open-source, any computer device can connect and will leverage its GPU to speed up critical research.

Keep it as an emergency backup

Let’s face it, chances are you’ve lost a smartphone somewhere in the last few years. Whether you got drunk on New Year’s or mugged on your way to the shop, for a moment there you were left bewildered and disconnected from the internet hive mind. Scary isn’t it?

Keep an old phone in a hidden spot of your car, office or home. You don’t necessarily need a SIM card as you can either run to the nearest Wi-Fi hotspot and contact your loved ones or contact emergency services which are toll-free. In South Africa you can dial 112 or 107 if you’re in Cape Town.

The remote you’ve always been looking for

Use it as a universal remote. Though most TV apps have dedicated remote control features you can access via your smartphone and tablet, what about operating your computer? Apps like Unified Remote are free and can turn your Android device into a WiFi or Bluetooth universal remote control for your Windows PC, Mac and Linux.

You can remotely control everything from offline software like Windows Media Player, VLC to online services such as Netflix, YouTube and your desktop.

The ideal setup for this would be having your computer connected to your TV and simply slouching back into your couch, grab some beers and popcorn, and never get up.

Make money and mine for Bitcoin

Apart from selling your old mobile device, there are other ways of making moola.

While it might be disposable, your iPhone or Android has powerful GPUs that can still be used. That in turn means you’re able to connect your mobile computer to the global hive mind by helping solve the digital currency’s blockchain.

In this case, DroidMiner BTC/LTC Miner or Easy Miner for Android are pretty badass.

Run the app, leave your device in a charger and forget about it. Your smartphone will now generate a minor yet steady stream of Bitcoins. I didn’t manage to find an iOS app but there’ll probably be one in the near future.

Turn it into a really expensive photo frame

In case you don’t mind having an expensive computer hanging on the wall or framed at your office desk, download an app like Dayframe, set it to “Slideshow” and watch it stream and share all your photos from Facebook, Instagram, Tumblr, and so forth. You can set it to update your photos daily.

Geek multitasking

Use it as an extension for your computer. If your smartphone has a big enough display, grab a stand, download an app like iDisplay or Air Display, and Bob’s your uncle: you have a dual monitor setup. In situations where this might work best is getting your Twitter feed or Music stream up on your mobile while leaving the hands-on stuff for your computer monitor.

If you’re using an iPhone or an Android with a smaller display, you can always use it as an extension to your computer’s keyboard. See apps like Touchpad and Remote Trackpad to gain a helping hand. The later can also double as a soft keyboard.

Never get lost in your car

Use it as a fixed navigation device. Churn out some money for a decent smartphone mount or arm that would hold your device in place either on your car’s windscreen or dashboard. Now download Navfree for offline use (just enable your device’s GPS and remove the SIM) or get Google Maps and Google Navigation for more accurate results.

Though you require an internet connection to use Google Navigation, you can always download specific maps and store it for later. If you want your device fixed, find a car charger as well. Just remember to remove it when you’re done driving to avoid break-ins.

From making money, spying on people, decor and getting around town, don’t throw away old devices, and think twice about giving them away or selling them. Which are your favorite hacks and which ones did we forget about? Let us know in the comments below:

Image by Mike Mozart via Flickr, Redmondpie, The Next Web, Recombu.