Even though a Mac mini only occupies about 60 square inches of desktop space, you still might want to keep it completely out of sight. There are a number of ready-made brackets available that will let you easily mount a mini either under a desk or directly behind an LCD display.
Sonnet MacCuff Mini Mounting Bracket ($57.99)
This steel bracket comes in two sizes. One fits the new 2010 Mac mini and the other fits all previous models. This is probably the most versatile of the lot, as it will mount either under a desk or to a VESA mount on the back of an LCD display. It features a steel locking bar for security and it comes with a 35cm short monitor cable and mounting supplies.
This bracket is designed for the 2010 Mac mini form factor, but Macessity also manufactures a similar “Hang With Mi” bracket for the older-sized minis. These units do not have holes suitable for VESA mounting and they are only designed for use under a desk. They do, however, have a built-in powered 4-port USB2.0 hub, which is nice if you plan to also mount USB devices out of sight. An optional swivel mount is available if you need to be able to rotate your computer while mounted.
Mac Mount (£14.99)
Although the picture below shows these relatively inexpensive acrylic mounting brackets being used to secure a G-Tech G-Drive, they are also designed to work with a Mac mini. They can also be used to secure an Airport Extreme.