Forget the stereotype of the curtain-twitching pensioner keeping tabs on your comings and goings - a new wave of nosy neighbour is in town and they are watching what you spend.
Thanks to the internet, it has never been easier to find out who owns property, what they paid for it or how much they are forking out in council tax.
What is more, online searches are impersonal and cheap - or even better, absolutely free.
But it is not just your curiosity that will be quelled, your bank balance will reap the benefits too. The information you gather could help you get a better price when buying, or even cut the cost of your household bills.
If you want to find out what any property in your area has been sold for, visit a website such as Zoopla.co.uk. Here you can search for a property or an area by typing in the name of a street or village. This will provide you with a chronological list of every property sold there since 1995 – and, crucially, the amount that was paid.
There are considerable advantages to both buyers and sellers by obtaining price information so easily. Vendors can find out what similar properties have been selling for in recent months and so will know at what level to market their homes; buyers need not pay over the odds for a property if they know the going price.
Another way to get the same information is by using the online Land Registry at landregistry.gov.uk. This provides much more detailed information and is great if you want to look at the register or title plan of a property you own, find out who owns a specific property, discover the area a property covers, or contact the owner if you want to buy it.
Start by entering the postcode and house number or name and click on the search button. It is even easier if you have the full address as you can click on "detailed inquiry". There is even a way to search for a property if you have no information at all: just click on 'map inquiry'.
For properties you are interested in, you can download a copy of the 'registered title' for just £3. According to the Land Registry, searches are anonymous.
Cut the cost of council tax
Another way to cash in on your curiosity is with your council tax bill. Neighbouring properties are often in different bands, and this gives you scope to claim back thousands of pounds if you do a little prying.
Don't be afraid to query your council tax bill: it could save you a lot of money. It is really worth doing as any repayment will be backdated for as long as you have been living at the property.
In 1991, properties were given 'drive-by' valuations to assess which band they should be in. As a result, many ended up in the wrong band, causing some homeowners to pay more than needed. But the internet means it's now possible to check and challenge your band free of charge – and from the comfort of your own home.
The first step is to compare your property's banding with similar neighbouring properties by going through the council tax list at the Valuation Office Agency's website at voa.gov.uk (if your home is in Scotland, try the Scottish Assessors Association on saa.gov.uk).
Just enter your postcode and select your house number and it will give you the banding. Then do the same with your neighbour's number to see if they are paying less than you.
Another way is to visit the aforementioned Zoopla for a free search of the sales price of the homes in your area. This should help provide a reasonable idea of your property's current value if unknown.
Then you need to find out what the price of the average property was worth in 1991, when the council tax bandings were set. You can do this by visiting nationwide.co.uk/hpi and using the building society's house price calculator.
But it is important to keep in mind that this is about asking for a banding reassessment, which may not necessarily mean a decrease in your council tax. Beware that if you write to the Valuation Office for a reassessment, your council tax could go up.
Hack back your household bills
Did you know that the psychological effect of knowing that others are paying less than you can spur you on to change your own spending habits? According to a report by Policy Exchange, evidence from the UK and abroad shows households reduced energy use, for instance, when their bills were compared with more energy-efficient neighbours.
So knowing what your neighbours pay could actually cut your annual household costs.
Broadly speaking, people living in any given neighbourhood pay roughly the same for their household bills subject to a few variables, such as the number of rooms per house, number of occupants and claims history.
Based on this, and the data collected by comparison website MoneySupermarket.com about the typical cost of living in particular postcodes, you can match your location on its home bill checker and discover an estimate of what people in your area are paying. This means that you will be able to tell if you are getting a fair price on your utilities.
"This is a great way for households to be in control and identify where they can save cash – based on what their neighbours are forking out," says Dan Plant, editor-in-chief of MoneySupermarket.com.
And the savings are not to be scoffed at. According to the comparison site's data, half of consumers could save around £250 annually - with £180 on their energy bills and £70 on home insurance premiums.
Pay less for your broadband
You might be paying for superfast internet – but it doesn't mean that you are actually getting it. And it could be thanks to your neighbours.
This is because it's not just the provider you choose that dictates internet speed – how close your home is to a phone exchange, the quality of the phone line and wiring, and number of people using the same provider locally will all affect your speed.
Around 50 people are thought to use every connection at an exchange so if you can see that everyone on your street is using one company for their internet, it might be worth considering using the next best provider to avoid traffic on the internet highway.
However, research from broadband provider Hyperoptic shows that one in three people in the UK has admitted to stealing their neighbour's WiFi. What you may find even more worrying is that this is just the number of people who have successfully connected, nearly 40% admitted to just trying. But how can this be costing you?
If your neighbour 'piggybacks' on your Wi-Fi, they could cause you all sorts of connection problems, some of which can cost you financially; for example, heavy downloading might slow down that expensive broadband speed you have been shelling out for, or you might find a huge bill on your doorstep for going over the download data limit.
So how can you notice if you have a freeloader on your Wi-Fi network?
If you notice intermittent problems with your connection, or your broadband appears to slow down at certain times every day, you could have a problem with someone stealing your Wi-Fi from you.
The first thing to do if you suspect a Wi-Fi thief is get on the case and check your wireless network log. How you do this varies depending on your computer but if you look at your network and see more devices connected to it than there should be, you may have a problem.
To avoid this, turn on your WEP or WPA encryption. Many broadband suppliers do this straightaway and give you the 'key' or password when you set up broadband with them but if yours is optional, make sure it's activated. You'll have to check your router instructions to find out how to do this.