I have just bought a laptop which now shares our home wireless network. I also want to use it (occasionally) from my parents house, who aren't on the internet. Can I just take it there, plug the normal built-in modem into their phone line and sign up to a pay as you go dial-up service from that number? Will it have any effect when I return home and go back onto our home system?
I also have a laptop that uses my wireless network at home. When I took it up my mums, I plugged it into her phone line and connected to a dial up service, as you are thinking of doing. It had no effect on my usage back home and I still use the wireless.
You may need to check your Internet Explorer settings ("Tools/Internet Options/Connections") to ensure your "dial a connection" settings are enabled at your parents' house. You may also wish to set this back to "never dial a connection" when you are using your wireless network to stop the laptop trying to connect via the standard modem when you are at home.