Any laptop can be connected to the internet by 3 ways that i know of while traveling.
1. If you have a Modem card in the laptop, you can "dial-up" to the internet using a local phone line in a hotel/shop/home/etc.. the exact same way you would if you had dial-up internet on your home PC instead of ADSL or cable.
I.e. Your ISP gives you a phone number to connect to for your local area. You enter this in your dial-up properties in Internet Explorer under the connections tab, then "connect" via it.
2. Most mobile phones come with a cable to connect it to your PC, and some software utilitys as well. When you connect your mobile phone to your PC you should also be given the option to install drivers that will enable your PC to use the mobile phone as a modem, thus you willl be able to connect to the internet the same way as in #1, just without having to actualy be plugged into a wall socket.... so you could do it in a car provided you have signal
Using this method it is entirely posible to connect while on a Plane... However i beleave using a mobile phone on a plane is a "Jailable" offence in most countries and could Endanger your life and that of everyone else on the plane.
3. If you are staying in a hotel, most medium to high quality hotels will have In-Room internet access via their in-house network.
To use this, when checking in they will give you a little card with instructions how to setup your PC to work with it.... basicaly you plug the Network card of your laptop into the port on the wall in the hotel room then tell IE not to make a Dial-up connection, but to instead "detect setings automaticaly" under the LAN settings.