I recently used the Apache commons net package in a project to create a small telnet client that automated a login process. It is hard to find a lot of documentation on TelnetClient but there are some examples. For what I wanted to use the telnet client for I ran into a problem because I needed the connect call to time out. Try as I might I couldn't get setDefaultTimeout to work as advertised.
After multiple attempts to find a good free diagraming application I think I have found a decent solution. I'm not creating enough diagrams to justify buying something expensive and I don't feel like finding a graphics designer to make Dia diagrams prettier. If you have a Mac you are probably not in as bad a situation since you can buy OmniGraffle for $79. But for those of us without a Mac or who are just very cheap I think the best solution starts with Inkscape. I've put together a list of 10 tips that will help make better looking diagrams with Inkscape.