MyTravelAccess.com http://www.mytravelaccess.com is exactly what you need. It is a Pay-As-You-Go Internet access to use when you travel. It has tons of access numbers and it can be used in over 70 countries. It is a good alternative to WiFi and hotel boradband.
While some may argue that dial up is slower than the high speed access offered by hotels, you must also take into consideration that you are sharing that access with other users in the hotel and that may affect your connection.
Some hotels have restrictions on their Internet access which allow you to receive e-mail, but you are not able to send e-mail. If you use your own ISP, you still have that ability. It is no different than using your home computer to access the Internet.