"Use Linux? Have a flaky cable modem or DSL hookup? If you do, and you leave your computer unattended, you'll return to find zillions of network error dialogs. Here's a quick solution.
"First off, here’s the netrepaird script. It's a simple script that attempts to ping network addresses (that you can define yourself), and if all pings fail, it'll attempt progressively agressive measures to repair your network connection. It's really low-tech, but it works..."