I bought an Arduino Uno recently to use when building prototypes. Using MCUs soldered to veroboard is nice, but it is not great for those projects where you just want to try something quickly. Thats where the Arduino comes in handy, now I can wire up something on a breadboard or solder a few things on a veroboard and connect the Arduino to control it.
A nice thing with the Arduino is that it uses an AVR MCU which means I can use my usual development tools such as AVR GCC when developing software and then transfer the code to a more permanent version later on.
