Making clever use (or reuse) of stuff that's just lying around is a staple principle here at Lifehacker, so we figure there's no better way to finish that coverage than with a roundup of our favourite recycling and repurposing hacks. Enjoy!

It happens to us all occasionally -- leftovers lurk in the fridge long enough to be both unidentifiable and scary to open. Lifehacker reader Nick offers a neat trick for getting rid of those odiferous problems without unnecessary nastiness.

If you want to recycle an old mobile phone, it's pretty straightforward no matter where you live. If you want to dispose of an unwanted PC in a responsible fashion, your options may be more limited, and government pushes to establish better national regulations appear to be stalling.

Our Earth Month coverage throughout April here at Lifehacker is part of a much broader effort; our sibling sites Gizmodo, Kotaku and the Sugar network are also looking into all things environmental. Here's a round-up of our favourites from the past couple of weeks.

You've planned carefully to score yourself a cheap airline ticket -- why jack up the budget by spending a fortune getting a taxi from the airport? Instead, check out Lifehacker's comprehensive guide to public transport options for Australian airports.

Buying a new mobile phone is always exciting, but in this mobile-saturated nation getting a new device invariably means working out what to do with the old one. As part of our ongoing Earth Month coverage, here's Planhacker's comprehensive guide to options for disposing of your old phone.

Just because a product claims to be "green" doesn't mean it will always deliver on that promise, and actually checking up on it can be difficult. So it's reassuring to know that regulatory bodies do keep an eye on this stuff. Right now, the ACCC is taking green energy supplier Global Green Plan back to court for failing to actually deliver on its promise of selling environmentally-friendly power plans.

Dear Lifehacker, A simple question: what can I do with a 32-inch spare flat-screen TV? Thanks, Bigger Screen

We're all looking for ways to cut costs around the home. If you have a fancy refrigerator that makes its own ice all day, it's time to turn that sucker off, as it is one of the worst offenders of secret energy consumption.

Our Earth Month coverage throughout April here at Lifehacker does not stand alone; our sibling sites Gizmodo, Kotaku and the Sugar network are also looking into all things green. Here's another quick selection of our favourites from the week just passed.

We've been talking about what to do with old books this week as part of Earth Month; I've been lucky in that the books I've stored in my garage haven't managed to become musty during that time. But what can you do if you do have a cherished old volume that smells as if it's been stuck in a vat of festering yoghurt for a decade?

Purely in terms of reducing energy bills, making the IT systems in your workplace "greener" can save a small fortune, which is always a good thing to boast about on your CV. Here's some simple strategies to help the environment in your office.

There are plenty of sites which offer cash for old mobile phones. ReGadget takes a similar approach, but expands the range of gadgets you can send in, covering phones, cameras, MP3 players and consoles.

There's all kinds of stuff which I need to sort in my house as part of the Unclutter Diaries, but there's no doubt that books are the dominant problem. Here's how I'm going about sorting and redeploying them.

Dear Lifehacker, I’m a student using a MacBook Pro for uni on which I’ve got Mac OS X & Windows 7 dual booted. I’m constantly switching between the two depending on what I need to do (though Windows is my preferred OS). Recently I’ve noticed that the battery lasts longer on the OS X side than it does on the Windows 7 side, even when only browsing the internet. Why is this? Does this mean that OS X is more energy efficient (& hence environmentally friendly) than Windows?

We're running Earth Month coverage throughout April here at Lifehacker, and our sibling sites (Gizmodo, Kotaku and the Sugar network) are also offering up their own green living insights. Here's a handful of our favourites from the week just passed.

Leaving a charger plugged in to the wall for your mobile phone can seem convenient, but it has two disadvantages: you can end up with a bunch of chargers lying around and looking tangled and ugly, and your chargers will draw a small amount power even when there's nothing connected. Belkin's Conserve Valet charger station is a neat way to solve both problems.

We all know that using the power management facilities on our PCs is a sensible idea to reduce energy usage, but it's often hard to conceptualise just how much difference doing that can make. The University of Sydney introduced automated power management technologies into its student labs, and saw huge reductions in its environmental impact as a result.

A lot of our emphasis during Earth Month is going to be on more effective energy usage, but there's another equally important side to reducing your impact: not needlessly buying new stuff, and making better use of the stuff you have. I'm going to try and do that myself, and track my progress in the Unclutter Diaries.