What type of phone do you got some telephones have to option to be used as wireless acces point. This way of using the internet with a moblile phone is called tethering. Just look on google: How to phone name tethering. You will find plenty of guides.
Keep in mind it will use a lot of data. Most providers aren't happy with people who are doing this. I would suggest to contact them and ask if they support it before getting big bills for data usage.