Getting Close on the Host
If your desktop sharing needs don't extend past Windows, here are some software options:
pcAnywhere is the most popular remote control software, by Symantec. A mature product at version 10.5, it now includes an option to install without rebooting the computer.
LapLink Gold is a relative newcomer to the field, even though it has been providing file transfer capabilities since the days of DOS. It addresses one of the "chicken-and-egg" problems of remote control with the ability to remotely install itself on one PC from another.
Altiris now offers pcAnywhere's old rival, Carbon Copy, as Carbon Copy Solution. It is available as a Web-based client.
Like many software programs, desktop sharing is now available as an outsourced service. GoToMyPC by ExpertCity is a hosted service that can be accessed by virtually any modern computer. After logging in, a lightweight client is downloaded, which allows a Windows PC running the software to be controlled by the Java applet. Because it is a hosted service that uses a unique identifier for each PC, GoToMyPC is especially adept at working across firewalls; it can be used as an ersatz virtual private network.
GoToMyPC supports remote file transfer, but does not support sound or clipboard transfer. In addition to supporting non-Windows viewers, version 2.0 of the service includes better performance, an improved file transfer interface, and remote printing (the local machine must have the appropriate printer driver). GoToMyPC isn't the only way to remotely show a PC screen using the Internet. If you want to enable ad hoc viewing of a PC during a conference call, Web-based conferencing systems such as those from Raindance and WebEx can integrate screen sharing into their information sharing environments.