Cheap Data Roaming Avoid shock bills & slash costs

Using your network's 3G (or to a lesser extent 2G) signal to access the web is what costs big. Switch off your 3G signal to avoid any nasty big bills. You'll still be able to use the phone if it has w-fi capabilities or for listening to music or calling.

Many apps and programs, as well as the operating systems themselves, routinely check for available updates and download them automatically. This can use up hundreds of megabytes, racking up charges. So if you're keeping 3G on, turn them off to save on data costs. Here's how for iPhones and Android handsets.

iPhone. Go to Settings > Fetch New Data and then switch "Push" to off. Then change "Fetch" to "Manually" - this will stop your handset from scanning for emails and app updates every few minutes, which could run up a hefty bill over the course of your holiday. More info on the Apple website.

Android. Go to Settings > Accounts and Sync then untick "Background Data". This will prevent your phone from syncing and updating. You should also check the settings in each app, as there's usually the option to turn off auto updates.

Never use your network's 3G signal to download or stream films, TV or music. This will take huge chunks off data and can you see you faced with a bill of £100s or £1,000s.

If you've got a 3G Kindle, don't forget to pack it in your suitcase before you go, as it offers free mobile internet access across most of Europe and other countries around the world (see coverage maps). The idea is that, while overseas, you can download books or newspapers at no additional cost, even without wi-fi connection.

In the "experimental" option in the menu however, there's a web browser. It's black and white, and pretty basic. You can't watch videos of high-end graphical content, but for scanning info sites it's functional, and if you've got web-mail like Gmail you can use it for that at absolutely no cost.

The currently free app, Onavo, compresses data downloads for apps like Facebook, so you can do more with your download limit. It also works in 90 countries around the world, helping you minimise expensive roaming rates.

Onavo says it could reduce data usage by 80% and is totally secure as it doesn't store your data. It can't compress downloads for apps that stream content like the BBC iPlayer or YouTube, or VoIP apps like Skype. It's only available for iPhones at the moment, but an Android version will be launched soon. Onavo says it will start charging a subscription but it's free for now.

Alternatively, web browser Opera also offers a free data compression app for web surfing. The "Mini" mobile version of the browser is available for iPhones, Android and Nokia phones.

All iPhones have a function which allows you to switch off data roaming, which should mean no charges when away. However, complaints have flooded in from MoneySavers saying they have taken the necessary steps to disable roaming and have still been charged. Here's what you should do to avoid that:

1. Ensure software is up-to-date. Plug your phone into iTunes and follow the on-screen prompts to download any software updates before you go. O2 says a fault in a previous iPhone software version led to erroneous charges.

2. Turn off data roaming. Switch off data roaming BEFORE you leave the UK and keep it off. While it is on, some apps trigger data downloading even when you're not browsing the web. You may also be downloading emails inadvertently.
   
   When you buy an iPhone, data roaming should be "off" by default. You can check by going to settings > general > network, and move the Data Roaming slider to "off".

Current EU regulations mean providers have to warn when you've nearly used €50 (around £44) of data in a month when roaming in the EU. When you hit this mark, your mobile provider should cut off your mobile internet service until the next billing month begins.

You can opt-out of the cap warning or arrange in advance to have a higher limit if necessary, though this isn't a good idea. Also be warned that by signing up for certain data bundles you'll be automatically opted out. Speak to your mobile provider before you go to check you're covered.

WARNING! The cap only applies when using mobile internet in EU member states, NOT all European countries. Some popular holiday destinations, including Turkey, Croatia, Eygpt and Switzerland are not covered by this warning cap.

If you're using a travel-guide app make sure it's one that works offline. This way you should still be able to access maps and reviews without hammering your data allowance.

TimeOut's apps offer this for example, others should tell you before you download them.

Downloading attachments will eat into data costs, so don't do it. Even better, if you currently manage your emails with a program like Outlook or Thunderbird (and you get a lot of unnecessary ones), you may save data by signing up to a web-based service like MS Live Hotmail, Yahoo Mail or Gmail.

It is possible to re-direct your emails there and view them without downloading, so if a friend decides to send you party pictures when you're away in Spain, you can choose not to download them 'til you get back (see Martin's blog). Also, select your emails to be "manually retrieved", rather than "pushed" through. This will limit your data use.

One way to seriously boost the number of wireless networks available to you is to sign-up to the fon scheme, which has over a million members worldwide.

The idea's simple, you buy a special wireless router (£30) which splits your connection in two; one secure part for you, and one open part for other members of the fon community, or "foneros", who in exchange offer you use of the open part of their own wireless networks, wherever they are in the world.

To work out if you'll benefit from joining, check out fon maps, which shows hotspot locations worldwide (click the "hotspots active in the last hour" button for an up-to-the-minute representation). Given the cost of roaming in some places, it may well be worth the one-off £30 spend for continuous access to fon hotspots. Report your feedback and see what others say in the Fon discussion.