Do you have eight gadgets when actually your mobile phone does all the same tricks in one? Do you keep CDs in your home when you own the music in other formats? Do you pay for unnecessary subscriptions when you can get the same service for free online?
If the answer to any of the above is yes, then you could be wasting money. Plenty of us no longer need many of our regular purchases and services, because we have access to alternatives.
That means we can avoid paying for them again and potentially even sell off some stuff.
Here are seven things you could do without:
It's contentious, but bear with me. If you have an e-reader like the Kindle or a tablet computer then do you really ever need to buy a book again?
According to the International Data Corporation, more than 10.1 million media tablets were sold in the last three months of 2010, alongside six million e-readers. That's a lot of people who don't need to buy a real book again.
Project Gutenberg has more than 36,000 free e-books that you can download onto your computer, e-reader, tablet or even smartphone. Most of the well-known classics are available, so you can save a fortune.
It can also be much cheaper for new books. For example, I wanted to buy the latest George RR Martin novel; the newly-released hardback is priced at £25 but an electronic copy is £11.99 — less than half the price.
Almost six in 10 Brits use the internet to watch TV, films and online video, according to a uSwitch survey. If you're one, do you still need to watch normal TV?
You don't need a TV licence to watch catch-up TV like the BBC's iPlayer and so, unless you're watching or recording a programme in real time, you do not need to pay the annual fee.
With so many people using their computers to watch programmes after they've been broadcast, for example, through 4oD, there will be plenty of people who no longer watch 'live' TV at all.
You can still use a TV set for watching DVDs and playing games, as long as it isn't installed as a TV receiver. If it is then you need a licence. You can avoid the endless letters demanding payment by notifying TV Licensing, although be aware that you'll most likely receive a visit from an inspector.
Don't forget, if you watch TV as it happens, even online, then you do need to be covered by a licence.
When I was a teenager, I had mountains of music tapes, then when I was a student I had mountains of CDs. These days I can't remember the last time I used a physical disc to play music, and the growing popularity of iTunes shows that I'm not alone.
If you're buying music online and storing it on your MP3 player or even your phone, then maybe it's time to ditch your CD collection. Move fast and you could sell them before the rest of the country goes entirely digital too.
The landline is fast going the way of the dodo as individual mobile phones become the normal way to contact friends and family.
So you're potentially paying an unnecessary line rental fee, which you may think you need to get broadband in your home.
However, if you're a fairly lightweight internet user then talk to your mobile provider about whether it could be cost-effective to connect your computer to the web using your mobile — it's really very straightforward.
That also means that you can access the web wherever you are, you aren't tied to your home. Make sure your data allowance meets your needs, for example, 3 currently offers unlimited data packages.
SatNav hasn't just saved me time and effort; it's probably saved my marriage too - as a navigator on long journeys I apparently "didn't inspire confidence".
But why hang onto road maps if you're simply not going to use them?
If you don't have a SatNav yet then it's worth investigating whether or not your phone has a SatNav capacity. There are even free apps like NavFree.
Away from the car, smartphones now not only can store all the maps you need, but they also use satellite data to put a nice pin in where you are on the map and even which direction you're facing.
Calculator/personal organiser/most gadgets
Before buying any gadget, ask yourself if your mobile phone does it. Ofcom reports that more than a quarter of adults and nearly half of all teenagers own a smartphone.
If you have a high-spec phone then you can find cheap or free apps that do everything, from egg timers to pedometers, calculators and even a torch.
My mobile handset has internet access, meaning I can read every non-subscription newspaper online for free, so I haven't bought a physical paper in more than a year.
This doesn't just save money, it cuts down on paper waste and lets me read news and columns from more than one place, giving me a broader range of reporting and opinion.
And you can even get your phone to pull down an entire paper overnight, meaning you can read it in places without phone reception.