Multiple remote desktops have been a standard in Unix almost since its inception (think terminals), but Windows always seemed to be a desktop operating system usable by one person at a time. Not so, I say! Our friends at SalaSource have created a free, easy patch to enable multiple concurrent remote desktops on a single XP Pro (NOT Home Edition!) computer that is not part of a domain.
So what if you're part of a domain? Most of my business customers fit into this category, and as much as I hate to say it, it'll cost you some money to do it right ($550.00). Doing it wrong is indeed free - XP Unlimited offers the Enterprise version of the software, which has a free demo that is not crippled and never expires.
Using either of these tools allows two or more people to simultaneously use the same computer under different usernames, with one local user, and an unknown number of remote users - I've had as many as two remote and one local working at once with no serious degradation to performance on a fairly new Dell with a Celeron 2.8G CPU and 512MB of RAM.
This is extremely useful for organizations that can only afford one XP machine and would like to keep on using their clunkers like Windows 95 and 98 (which is unsafe at best due to viruses). Even more useful is using old computers with an open source desktop OS like OpenSUSE or another flavor of Linux and the rdesktop command - then a user on a crummy old computer that used to run Windows 9x can now use a reasonably secure, modern OS on their desktop and still have access to an XP computer to work in their preferred environment or to use applications that only work on Windows.