Arietta is a cheap, tiny Linux Embedded module powered by an Arm processor ideal for small DIY projects. You can order it today for only 9.99+shipping which in my opinion is a great bargain!

Look at the specs:

• Cpu ARM9 @ 400Mhz on Atmel AT91SAM9G25 SoC
• Ram 128 (or 256) MByte DDR2
• MicroSD holder hinge type for up to 32GB bootable Linux microSD (memory card not included)
• Placement for a IEE802.11 b/g/n Wi-Fi module with internal or external antenna (not included)
• Pads compatible with the Debug Port Interface pinout to have a direct access to the MPU serial debug port (TXD0,RXD0 @ 3V3)
• USB 2.0 ports lines (D+, D-):
• 1 hi-speed host/device
• 1 hi-speed host
• 1 full-speed
• UARTs: 3 ports
• I2C: 1 bus
• SPI: 1 bus with up to 3 chip select (5 to 50 MHz)
• PWM: up to 6 lines
• A/D converters: 4 channels@10 bit
• User configurable led on board
• No video and LAN interface.
• Size: about 25x50mm
• Power supply: single 3.3 Volt DC
• Line levels: TTL 3.3V (NOT 5V tolerant)
• Operative temperature range: -20 +70 °C
• Placement for 20×2 pitch 2,54mm (100mils) pinstrip (not included)
• Optionally available with mounted male straight or 90°C or female pinstrip
• PCB layers: 8

More information here:: http://www.acmesystems.it/arietta