DSL Internet access is a technology that permits connection speeds up to 100 times or more faster than a dial-up modem connection. DSL is generally considered more reliable with better per user throughput than other high speed Internet services such as the Internet on cable.
If you are currently using a dedicated line for Internet access then switching to DSL may not cost you anymore.
Additionally, you can talk on the telephone at the same time as you are surfing the Internet. There is no need for a second phone line.