According to Wikipedia a laboratory is:
... a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed.
I like to take a more expansive view and consider any space set up specifically to experiment in can be considered a laboratory. Whether this experimentation is scientific, engineering or artistic doesn't really matter. This expanded definition covers everything from an artists workshop to a chemistry lab and certainly fits many backyard workspaces.
Today it is exceptionally easy to acquire and learn how to use all the equipment required to set up a laboratory in your home and in fact you have access to many pieces of new technology that would not have been available to (or would have at least been prohibitivly expensive for) a commercial lab as little as a decade ago.
Take 3D printers for example - a device like the Solidoodle is available for around the $US 500 mark, there is a wide range of open source software available to generate and manipulate models for printing and the ABS plastic used for printing costs around 4c a gram. This price point (and the ongoing running costs) put it within the reach of a hobbyist (even more so if you share the cost amoungst a group rather than buying it individually). What was once a high end device used for commercial prototyping is now available to the individual to create custom items in single or low volume runs.
And once you have the printer there are a wide range of useful and interesting things you can print already available - the Thingiverse site has a vast database of models already made by others that can be used immediately. Even if you have no intention of designing your own components there are large libraries of mechanical components (gears, connectors and frames) that can be downloaded and printed out to build up your designs.
Electronics has been a favourite hobbyist pastime since valves became available, today the range and low cost of components (and complete modules) greatly extends the range of what is possible. A large range of computational components such as the low cost Microchip PIC or Atmel AVR microcontrollers make it simple to add smarts to your project (or reduce the complexity by implementing operations in software rather than hardware). Even if you don't have digital circuit design experience a pre-built module like the Arduino will handle that side of the workload for you letting you concentrate purely on the control circuitry.
More recently a range of cheap (< $US 50) single board computers capable of running the same operating systems that you use on your desktop have become readily available (the Raspberry Pi in particular has been getting a lot of press lately). This allows projects that are more intelligent, more interactive and more responsive to be built at a very low cost.
On The Garage Lab all of the technologies mentioned above will be used (in combination with more standard woodwork construction) throughout the projects. A lot of this, combining the different technologies, is a learning experience for so many of the posts and articles will be in tutorial format detailing what I've learned and how to put it in practice (including the failures and mistakes I make).
I hope you enjoy the site and the projects. If you have an idea for a project, or would like to write up one of your own projects for publication please feel free to get in touch.