JackDaniels, do you really imagine you can connect to your BT, AOL. Sky or whatever router while you are away from home?
Carandrog, you will find plenty of Wifi hotspots where you can use the internet abroad, such as bars or hotels. Some will be free, some will charge.
Mobile broadband dongle connects to the internet via 3G technology and will depend on coverage on can be hugely expensive.
hc4361 - Course I didnt mean that the OP would be able to use his home router whilst abroad - though if he is with BT for eg (as I was) they are more than happy to send you the dongle (sometimes they charge for it), and advise you of the charges etc when using it away from the home
So as I said the OP CAN contact his internet company and see what their rates are.