This is a develop board that I designed for on breadboard, has 5v voltage regulator, crystal, USB, and reset button. It's compatible with standard breadboards.
Flash 32KB
SRAM 4KB
EEPROM 1KB
4-channel DMA controller
8/16-bit AVR microcontroller
Breadbord compatible
5 x 16-bit Timers
16 x PWM outputs
12bit ADC's
12bit DAC
128bit AES/DES hardware encryption engine
5 x UART
7 x SPI
2 x I2C
1 x USB 2.0 full speed/low speed (12Mbps/1.5Mbps) device compliant