The latest low-cost, Linux-friendly ARM single board computer is the Orange Pi that's trying to ride off the success of the Raspberry Pi.
The new Orange Pi is a series of Allwinner-based ARM SBCs with there being the Orange Pi Mini, Orange Pi, and Orange Pi Plus. The Orange Pi Mini and Orange Pi use a dual-core ARM Cortex-A7 Allwinner A20 SoC with Mali-400 MP2 graphics. The Orange Pi Plus uses the Allwinner A321 quad-core Cortex-A7 SoC with PowerVR SGX544MP2 graphics. All three models ship with 1GB of RAM, SATA, and microSD storage support. The Orange Pi also features Gigabit Ethernet, 802.11g/n WiFi, USB 2.0, and expansion header.