http://www.mikroe.com/add-on-boards/communication/wifi-proto/

The WiFi Proto is a WiFi (2.4GHz 802.11b) module that implements the ZeroG ZG2100M wireless module, designed to easily implement Wi-Fi networking to any application. The WiFi Proto can interface to any host controller using a standard UART or SPI bus.

WiFi Proto main features:

• Single-chip 802.11B including MAC, baseband, RF and power amplifier.
• Data Rate: 1 & 2 Mbps.
• 802.11B/G and 802.11n draft 2.0 compatible.
• Low-power operation.
• API for embedded market, no OS required.
• Hardware support for AES and RC4 based ciphers (WEP, WPA, WPA2 security).