Smart money: Make sure your phone tariff allows you go online as much as you want
Some of you may simply use your phone to make and take calls and texts, but with 20% of worldwide phone sales now accounted for by smartphones, an awful lot of people are using their phones for a whole lot more.
Irish mobile users are also embracing having what is essentially a mini multi-media device in their pocket; Vodafone reported that one in two devices they sold in December was a smartphone and O2 saw their smartphone customers increasing by 44% year on year.
But there is little point in having a smartphone unless you are browsing the web, emailing and watching videos.
And if you do, can you be sure that your tariff includes enough gigabytes (GB) of data to enable you to do all this?
Streaming a video for two hours on your phone could use 1GB for example, so if your tariff ends there and you keep watching that video you could be in for a case of bill shock.
The good news for heavy users is that 3 has introduced "all you can eat" tariffs, which essentially means that you can use an unlimited amount of data and not worry about cost.
3 say they have no "fair usage" policy, meaning that they don't have a cut-off point if you use too much.
A spokesperson for 3 said they "reserve the right to limit the service available to an individual if they exceed 15GB to ensure that everyone has a fair share of the network" but even in that case "the customer will not be charged for any usage where they have exceeded 15GB".
These new "Flex Max" plans cost €40 for a mixture of 350 minutes and texts, €60 for 650 minutes or texts, and €80 for 1,000 minutes or texts, to be used as you choose.
Over at Meteor you can get a 2GB allowance for €50 a month along with 400 minutes and 400 texts or 1GB for €35 a month plus 200 minutes and texts, while at Vodafone their smartphone plans typically come with a 1GB allowance, whether you're paying €60 for 300 minutes and 300 texts or €80 for 500 minutes and texts.
At eMobile you can get a larger data allowance of 5GB for €84 a month with unlimited calls and texts, or a 2GB allowance and 500 minutes and texts for €59.
O2 offers 1GB for €60 with 700 minutes (currently double the usual) plus 150 texts.
But how do you know how much data you are likely to use?
If you're just emailing and browsing the web, chances are you'll never even get close to 1GB, never mind need an unlimited allowance. In fact, Vodafone say their average smartphone customer uses less than 200mb a month.
However, if you are downloading and streaming a lot of video or music, you'll be using a lot of your data allowance.
And if you are 'tethering', that is using your phone's 3G connection as a mobile broadband device for your computer, that will use a lot too.