The answer for many people is mobile broadband. Most people will be familiar with the idea of the mobile broadband dongle, which plugs into a spare USB socket on a laptop and gives you reasonably fast internet pretty much anywhere in the country. Such dongles can be readily purchased for £20-£30. But what if you have a (non-3G) iPad, an Amazon Kindle Fire or some such other wirelessly connected device? What if you are on holiday with other people and have several such devices and/or laptops between you? A single dongle isn't much use in these circumstances.
Fortunately, there is a very elegant solution available in the form of the mobile hotspot. This is basically a mobile broadband version of the wireless router you might have at home or in the office. It fits in the pocket or purse, connects to mobile broadband and then distributes the signal to any wireless device in close proximity. Most mobile hotspots - also known as mi-fi routers - can handle 4 or 5 connected devices, which can be laptops, tablets, gaming devices or anything else that connects wirelessly. Even better, there is no software to be installed as the mobile hotspot is totally self-contained.
Most of the big mobile operators including O2, Vodafone, 3 and Everything Everywhere (T-Mobile/Orange) sell these devices, typically around the £50-£60 mark. They are available on monthly contract for regular users, or pay-as-you-go for occasional users. Some of them have additional features, such as the ability to share a micro-SD card so you can even create a sort of portable mini-network as well.
The Apple iPad is available with or without a 3G connection. Models with 3G typically cost around £100 more than wireless-only models. Buying a wireless model and a separate mobile hotspot is cheaper and more flexible, albeit not quite so convenient.
Mobile hotspots are also useful as a fallback device for the home or office, for use in the event of problems with your ADSL or cable internet. If you are only a light internet user - say email and occasional browsing - you might even be able to get away with a mobile hotspot as your only internet connection. This is useful if you do not have a telephone line or only have one in order to get broadband but don't really use it for calls.