Part of the fun of owning an Apple product is buying some accessories to go with it. The iPod is easily the accesory leader, but I imagine we'll see more and more for the Mac mini as time goes on. Today I discovered the Flip by Belkin. Basically, it's a small peripheral that sits underneath the mini and allows you to share one monitor, keyboard, and mouse between it and a second computer.
Use the Flip to switch between computers, eject a CD and use connected speakers with either computer (and adjust their volume). Plus, there's no software to install on either computer.