More and more of us are using Bluetooth, the wireless technology which lets us link up our mobile devices using low powered radio waves.
Because it relies on battery power alone its range is typically limited to a few metres, although laptops can reach 100m.
Increasing numbers are walking around in a Bluetooth bubble
So far it has mainly been used to connect handsets to headsets but the uses for Bluetooth are now expanding rapidly.
Add a Bluetooth dongle to your iPod and you can stream your music to a portable speaker. Some MP3 players and many phones come with Bluetooth built in.
The Sony Ericsson Bluetooth watch vibrates when a text or a call is coming in and displays the name of the caller. It can even be used to control the music on a phone.
Dongles can also be used with PCs or laptops allowing files to be transferred wirelessly. Using a Bluetooth connection a GPS dongle can allow non-GPS phones to hook up to sat-nav.
Travels with Bluetooth
The Bluetooth market has got so big that some of the manufacturers have bought a sports car to show off their kit.
"We have a rear view mirror which can take over the functionality of your phone," said Bluetooth promoter Danny Devriendt.
"When someone calls, you get an identification inside the display of the mirror so it enables you very quickly to see who is calling you.
"Also, I can stream all of the MP3s that are in my mobile phone directly to the radio. And if you have an iPod with a little Bluetooth dongle or you have your laptop with your 40,000 preferred songs on it, all of that can connect to this thing."
And another practical on-the-road use for Bluetooth is in-helmet microphones allowing two bike riders to talk to each other.
Because Bluetooth is a wireless network that moves with you it works anywhere - even on a Tube.
Many people leave their Bluetooth turned on when travelling on the underground even though they cannot receive calls. It is a real drain on a mobile's battery.
The ability to find and contact other Bluetooth phones this way initially exposed us to being hacked.
Criminals could lift numbers and other info without us knowing but security upgrades over the past few years now make that much more difficult.
In fact, the most difficult thing you may find when using Bluetooth, is simply getting two devices to talk to each other.
Many people find this irritating, including technology journalist Barry Fox
"It's the pairing, the discovery, it's the computer jargon, it's the fact that when you want to use a phone with a headset or a computer, you've got to put it in 'discoverable mode', you've got to know what that is."
"You've got to know about passkeys, you've somehow got to persuade these reluctant relatives to talk to each other and it's so annoying because it could have been so easy," he said.
The Bluetooth Special Interest Group is an industry body that tries to make things simple. It sets the standards our devices will work to and its latest version Bluetooth 2.1 will be rolled out in products next year.
The group's executive director, Mike Foley, said the products are going to be more intelligent.
"When you get a new headset and mobile phone the first thing you want to do is connect them so the products can basically do that themselves: not hitting a button on the headset, no entering a pin, they just find each other, connect, you hit OK and they work from then on," he said.
The automation of pairing and passkeys is not the only feature, touch transfer is another. For example, to transfer a photo from a camera phone to a digital photo frame - both have Bluetooth - rather than pressing buttons they can be held within a few centimetres of each other. Near-field communication chips in each device tell Bluetooth it needs to do something - in this case transfer the photo.
Of course, you will need to buy all new kit to do that. And that is where a lot of danger lies for us - the consumer.
Bluetooth does not just come in one flavour, there is the Bluetooth that transfers files like the previous picture example, ones that stream stereo music, work with headsets or printers - they are all different types or profiles.
Now to make it easier, the Bluetooth industry body has established symbols for use on packaging - match the symbols on two products and they should work together.
But manufacturers do not have to use them. In fact, some big players are not. And if we make the wrong choice we will be left with two bits of kit that do not want to know each other.
And the dream of simple universal Bluetooth could be taking further steps backwards as companies rush to market with shiny new devices before a universal standard is agreed upon.
The Sony Ericsson watch only works with Sony Ericsson phones - there is currently no Bluetooth watch profile agreed by the major manufacturers. Nokia's GPS dongles also have limited interoperability - Nokia is working with a wireless maritime standard while it waits for the Bluetooth Special Interest Group to establish rules for GPS Bluetooth devices.
"I think that is the vendors walking away from their responsibility to the consumer," said mobile consultant Paul Rasmussen.
"These are Bluetooth products and as far as the consumer is aware they should interoperate. He buys product X and he expects it to work from product Y.
"The consumer could end up being very disappointed taking these products home expecting them to interoperate and they don't."
Both Sony Ericsson and Nokia told us they do make clear which phones will work with which devices.
And they are not the only ones who do not want to wait for a Bluetooth standard to be agreed before selling their creations.
So buyer beware, when it comes to buying Bluetooth. Check everything works together first or blue is all you will be feeling.