Here is module for the .NET Gadgeteer that allows you to connect other modules in daisy-chain configuration using only one port. This is a proof of concept for Arduino based Gadgeteer DaisyLink module.The Gadgeteer DaisyLink protocol allows to chain up to 126 various modules on one socket. The protocol is based on I2C-based EEPROM interface.
There is a new Wi Fi module around. It supports UART, I2C, SPI, and Ethernet interfaces. The board has a RT3050 320Mhz CPU with 8MB of flash memory and a 32MB onboard RAM chip. It is built to support Linux based embedded systems via the OpenWRT. Via the contact form.