How much is that computer in your attic worth? Not how much you paid for it, but how much it is actually worth today? Half? Less than that? Don't forget to take a few quid off for the scratches down the side, and the USB port that stopped working after your little nephew attempted to get files off a chocolate biscuit.
And don't forget to take into account the kilo of cake and crisp crumbs that will have built up in the keyboard. This could add or detract from the value depending on how hungry your buyer is.
But your old hardware? Let's be honest, it's not going to be paying off the mortgage anytime soon.
That is, unless it's of the same sort of calibre as some pretty special kit going under the hammer at Christie's later this month. Tech treasures in the auction include an example of the first computer built by Apple, a WWII Enigma cipher machine and documents from one of the fathers of computing, Alan Turing.
One of the lots is an Apple I - the first commercial computer built by Apple - which is expected to fetch between £100,000 and £150,000. Not bad considering it had an original price tag of $666.66 - and that's before you add in the cost of the screen and keyboard, which you had to buy separately.
Also included in the lot is the original packaging, instruction manuals, and a letter written by Steve Jobs to the original purchaser about the best screen and keyboard to use with the Apple I.
It also features a Scotch C60 cassette tape containing the Basic programming language, which made the Round-Up come over all nostalgic about loading programs from tapes, if only for a second or two.
So who knows? Give that old PC in the loft another few hundred years and it might be worth something to your great-great-grandchildren. But don't bet on it.
Still, if this trip down memory lane - talking of memory the Apple I had 8K of RAM - has got you in the mood for nostalgia, then you'll love silicon.com's special photo feature on the evolution of the datacentre, featuring some of the giant, prehistoric computing beasts such as the Univac I before fast-forwarding to the sadly less glamorous modern day.
Featuring lots of sensible-looking types in natty sports jackets, it's not just a history of the datacentre but also a history of geek fashions in the past 50 years. And check out the very slick-looking IBM office that looks like it could have been used as a set for Mad Men.
Sigh - if only the server room of today was so swelegant ...
Social media is a wonderful thing, creating new ways for us all to keep in touch with friends close and far flung. And, of course, embarrass ourselves in front of them in new and painful ways.
For, while a drunken comment slurred to a friend in the pub after a few drinks is forgotten within minutes - or less if they are as 'refreshed' as you are - the same comment scrawled on, for example, the Facebook wall of an ex-girlfriend may linger a little while longer. And cause more trouble. And angry visits from her new boyfriend.
Similarly, at 3am it may seem like a great idea to upload photos of just how much fun you're having dancing a conga with the rest of the team after the company offsite strategy day, but the next day it may not remain so, as both your hangover and your MD's ire kick in.
Fortunately, for all you social media exhibitionists out there, and with the traditional Friday night visit to the local pub looming, help could be at hand.
A couple of years ago Google attempted to save us from ourselves with its Mail Goggles, which asks you maths questions before letting you send an email at certain times, like on Fridays after the pubs shut.
And now a similar tool, with the tagline, "Nothing good happens online after 1am", could save us from social media catastrophe, too.
Install the The Social Media Sobriety Test browser plugin and during the hours you set - say 11pm to 3am - it will make you pass a test before letting you into your Facebook, Twitter or YouTube accounts. As the plugins website puts it, pass the test and post away, or if you fail, "maybe just go to bed".
Wise words indeed.
And those of you who struggle to avoid email disasters even when you are in the office and sober might want to check out the column on silicon.com this week featuring five ways to stop email blunders, too.
And of course don't forget you can keep up with silicon.com via your preferred social media network. You can check out the silicon.com Facebook page .
Join our LinkedIn group and follow us on Twitter. None of which is likely to be updated at 3am. Especially now the powers that be have changed the password again and won't tell the Round-Up what it is.
And finally this week: an insight - if one was needed - into the internet habits of the UK male.
A survey of 1,183 UK men in relationships found that one in three mostly uses the internet to read general news, 17 per cent mostly go online to read sports news and 14 per cent mostly use it to shop.
So far so good.
Oh, and then there is the eight per cent who admitted to mostly using the internet to look at adult sites. The survey by myvouchercodes.co.uk also found that of that eight per cent, one in four admitted to doing this specialised "research" while his partner was in the next room.
And a worrying 16 per cent claimed to have pursued their delightful "hobby" while in the office. Reeeeal classy.
But eight per cent of men confessing to using the internet mostly for smut? The Round-Up isn't sure it that's a sign that men are getting more honest in their responses to surveys, or that 92 per cent of men are still big fibbers...
That leaves just enough time for a quick look at the rest of the big stories on silicon.com.
When is a cloud not a cloud? When it's a mirror, of course. silicon.com editor Steve Ranger gets all metaphysical when pondering what Steve Ballmer and Larry Ellison have to say about cloud computing.
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