From Ladislav Sedivy:
Keep your Dial up connection (modem or DSL) active. There are many situations when you need your computer to stay connected at all times. For example when you run a web, ftp or telnet service. Unfortunately the modem or DSL connection often stop responding or just disconnect. An easy remedy is to reconnect the connection manually. Obviously this doesn't help when you are 100 miles away and you absolutely need a file from your machine.