JavaShare is a Java program that links to the Beshare network. No file uploads or downloads, but it does let you keep an eye on the chat going on while you are working on a non-Haiku computer (Mac OSX pictured below) with a working Java installation. Just double-click the Jar file. It even runs on Haiku, I am told, though I am not sure what the point of that would be!
Download it here. The zip file is called Javashare2, but the app inside states that it is version 1.3. Don't even ask, it's been a long time.