EVDO is the 3G internet access technology for CDMA platform, the Evolution-Data Optimized(EVDO) technology offers mobile broadband speeds upto 3.1 Mbit/s.
I have been providing internet access to my Raspberry Pi via an TP-Link WiFi 3G Router, however we can directly connect a GSM/EVDO 3G dongle to any Linux computer and make it act like a WiFi access point using Linux utilities like WICD Network Manager. Configuring a EVDO modem to work on Linux can get a bit tricky, here is a simple to follow howto guide on setting things up.