There are many good reasons why IT managers would want to display and even control a remote PC. In early mainframe days, computers were simply too expensive for everyone to have one on their desk, so the computer shared time among different users. Many UNIX systems, such as Sun's Solaris and Linux, can still operate under this principle. They are fundamentally "multi-user" systems that let users have their own displays.
Nowadays, though, the driving reasons revolve less about cost than convenience. A user may need to view a document on another user's screen, or remote users may need to access a machine in the office from the road with a notebook or even from a hotel business center.
In any case, what separates remote desktop programs from simple file transfer programs is their ability to control and display the output of one PC on another, giving the effect of being in front of a PC from 1,000 miles away.
Depending on the task, platform, security concerns, and budget, a number of different approaches can help your users "reach out and collaborate with someone."
Virtually Any Platform: VNC and KVM
VNC, or Virtual Network Computing, originated at AT&T and runs across many operating systems, including classic Mac OS, Windows, and UNIX. While its performance and features don't stack up to commercial offerings, VNC is a free and straightforward way to view remote desktops when budgets are tight. VNC's operation is typical of many peer-to-peer remote solutions. A client logs in to a server with a password and can then either view that PC's screen or remotely control it.
KMV switches are another multi-platform approach to remote computing, which are named for keyboard-video-mouse after the kinds of connections it uses. Typically used in server installations, network managers have used KVM switches to remotely view multiple computers using a single keyboard, monitor, and mouse. One advantage of such switches is that they need no client software and work with any operating system (assuming that the computer supports standard VGA and PS/2 or USB ports).
Avocent, the KVM market leader, has now found a way to route KVM signals over the Internet; instead of being confined to a 25-foot cable, remote terminals can be miles away. The flexibility will cost you, though. KVM switches can run into the thousands of dollars, and the IP-enabled ones are among the most expensive of the lot.
While VNC and KVM switches work on Macs and PCs, Timbuktu from Netopia (formerly Farallon) is the only commercial package that allows Macs and Windows to share each other's screens and is also the first commercial product of its kind to work with Apple's latest operating system, Mac OS X. For those still on classic Mac OS, Power On Software offers a product called Screen to Screen, which is mostly geared toward lab-like environments. It offers the ability to see thumbnails of multiple screens at once, and to broadcast a PowerPoint slide show to them. Apple has also just announced a similar product called Apple Remote Desktop, which works only with Mac OS X.