Looking for compact but flexible, simple, and cheap development board? You should consider this nice list of microcontroller USB-Stick tools. These are special development tools that include all necessary hardware and software in a portable USB stick. Most of them consist of two parts – a USB stick and attachable target board.
For instance, eZ430-RF2500 is the world’s smallest low-power wireless development tool. At only $49, the device includes a USB emulator to program and debug your application in-system and two 2.4-GHz wireless target boards featuring the highly integrated MSP430F2274 ultra-low-power MCU.
All the required software is included, such as a complete Integrated Development Environment and SimpliciTITM, a propriety low-power star network stack, enabling robust wireless networks out of the box. The MSP430F22x4 combines 16-MIPS performance with a 200-ksps 10-bit ADC and 2 op-amps and is paired with the CC2500 multi-channel RF transceiver designed for low-power wireless applications.
If you want to try a separate microcontroller, then you can choose other USB stick development tools like ST microelectronics ST7FUS-PRIMER, STR9-Comstock, Freescale ZSTAR demo board with an accelerometer, NXP-Hitex LPC2468 ARM7TDMI based LPC-Stick with external SRAM, user pins and LEDs, and ATMEL RZRAVEN 2.4 GHz Evaluation and Starter kit that includes a wide range of low-power wireless applications like IEEE 802.15.4, 6LoWPAN and ZigBee networks.