We've all got that draw, cupboard or shoebox where our replaced tech is resigned to live for the rest of time - old battery-less remote controls, GameBoy Colors and that weird first iPod with the Firewire port.
Your unwillingness to throw anything away may be about to make you a mint though. Like classic cars, fine art and shamefully still-boxed Star Wars toys, there are a few bits of tech history that are still worth a fair bit of cash. If you've got any of these in your attic, the beers are on you.
1. IPOD CLASSIC
Born before 1990? Chances are you've got an old iPod Classic sat in your bedside draw. Sadly, yours probably isn't going to be worth $20k (£14,000) like this one that popped up on eBay recently. The second-generation model of Apple's era-defining MP3 player fetched a mass of money thanks to its mint in-box form that still featured the original, factory-sealed plastic wrap.
This isn't the only iPod to fetch a serious sum either. Early special edition models and boxed pre-click wheel units have fetched up to $100,000 in auctions. Bet you wish you'd treated your disc-man replacement a little better now, right?
2. E.T. ATARI CARTRIDGES
It's not just successful tech that appreciates in value, some of the biggest flops in history can garner the big bucks too, even if they're covered in dirt. That's no truer than with the 1982 release E.T. the Extra-Terrestrial for the Atari 2600. This game was so bad that thousands of copies were consigned to a landfill site in New Mexico. Seriously.
With word of the mass game grave having turned from fact to folk tale, 750,000 copies of the game were dug up in 2014 proving the stories were true. In the 21 years since they had been buried, the stories of the game's complete crappiness saw prices jump to a massive $1,500.
3. THE VERY FIRST SONY WALKMAN
OK, so your first foray into portable music isn't going to make you rich, but, thanks to the hipster movement and some decent Guardians of the Galaxy-inspired nostalgia, that past-its-prime product could still sort you a decent bit of beer money. You'll need to have been an early adopter though.
Your '98-released plastic-fantastic copycat device from Argos really should be consigned to the recycling bin, but if you've got a 1979-release Walkman TPS-L2, your bank balance could soon look a whole lot healthier. With units having shifted for $900 (£627), throw in some classic cassettes and you could make enough for a new iPhone 6S Plus.
4. ORIGINAL IPHONE
When it first dropped in 2007, the original iPhone marked a seismic shift in mobile phones that Apple's rivals are still playing catch-up with almost a decade later. If you were Billy Big Bank Balance back then and dropped $599 (£417) on the handset when brand new, you could be in line for a decent profit.
You're going to want to have kept this thing in mint, factory-sealed condition for it to be worth anything though. Used units can be picked up on eBay for under £100 - that's still impressive price retention - with mint, factory-sealed models having fetched up to $15k (£10,440) in online auctions.
5. 1990 NINTENDO WORLD CHAMPIONSHIPS GOLD EDITION
It's not just games consigned to landfills that can bolster your bank balance - rare and limited-edition ones can make mortgage repayments a whole lot more comfortable too. For games collectors, things don't get much rarer than the 1990 Nintendo World Championships Gold Edition cartridge.
With just 26 copies in existence - and originally handed out exclusively to winners of that year's Nintendo Power competitions - the gold NES cartridge holds a trio of classic games: Super Mario Bros, Tetris and Rad Racer. So, how much will this piece of 8-bit history set you back? Well, you're going to want to write a cheque for north of $15,000 (£10,440).
6. BITCOIN
Bitcoin's been tipped as the future of digital currency for a number of years. While it's yet to take over from cash and card transactions, it has appreciated massively in recent years. If you jumped on the Bitcoin bandwagon early then, your small-scale investments could now have you rocking out country clubs and riding diamond-encrusted unicorns to the spa.
You might not know the windfall you're sitting on either. Late last year, Norwegian Kristoffer Koch checked a digital wallet he'd filled with 5,000 bitcoins while writing a thesis on encryption back in 2009 - he'd bought them for just 150 kroner (£15.90). When found, the bitcoin treasure trove was worth a cool 5 million kroner (£530,000).
7. APPLE I COMPUTER
OK, the chances of you forgetting you owned Apple's original product are pretty slim, but if you're ever clearing out a relative's house or decluttering the far corner of your new gaff's attic, you're going to want to keep an eye out for this unassuming bit of kit that just happens to have been crafted by the hands of Steve Jobs and Woz.
With only around 200 ever made, and just 6 fully functioning models still believed to be in existence, a working unit was sold in October 2014 for a staggering $905,000 (£630,000). That's a massive mark-up on the wooden computer's original $666.66 asking price.
8. TI PROTOTYPE MICROCHIP
You wouldn't turn your nose up at finding any of the above in your retired tech arsenal, but they all pale into insignificance when compared with this, the godfather of Antiques Roadshow-worthy gadgets. Designed for Texas Instruments back in 1958 by engineer and Nobel Prize winner Jack Kilby, this prototype microchip is modern computing's version of the big bang.
The foundation for all future progression, it's more than a piece of tech history, it's a defining technical breakthrough in human evolution. As such, you'll need to be some sort of oil baron or Saudi prince in order to afford it. Put up for auction in 2004, reputed auction house Christie's valued the prototype chip at £2 million - although it then failed to hit its £1.2 million reserve.