LogMeIn is a remote desktop application that works on both Macs and PCs, letting you control and access files and data from one computer on another. It has several versions, including a free one that lets you control your computer remotely using a different mouse and keyboard. Advanced versions add in remote printing, drag-and-drop file transfer, and support for several people controlling the same PC simultaneously.
We like the service because its free flavor is so incredibly useful in times when you need to access something from your remote PC and don't want to mess with the lackluster solutions that come built-in to most computers.
Winner: LogMeIn (LogMeIn.com)