Papercut. School uses it. Businesses use it. It's a cool tool (see what I did there) to keep track of print costs for billing purposes whether for a school or business. But it's not without its issues (a lot of them user-error).
Remote Desktop. Do you use it? It can be a headache, but generally helpful for those who need to work remotely. What is it, what does it do, what's it used for, and how is it different than VPN? All this and our regular Yahoo Answers and other shenanigans.