What is EVDO ?

The short answer, EVDO is the acronym for Evolution Data Optimized.

This technology utilizes the CDMA Cellular networks to provide much faster data transfer speeds, broadband speeds (400-900K) in most major markets. Both Sprint and Verizon have offerings for this service with unlimited access for ~$60 per month, or tethered (phone as modem) plans for around $40.   

Both carriers have updated much of their systems to run "Rev A" EVDO, which runs about 50% faster in their service area.   All the current EVDO cards or modems are backwards compatible with the previous technology, 1xRTT, which will operate in the fast dial up range (50-100K), so if you are off the beaten path, chances are you will still have access, it will just be slow compared to what you are used to.

Security on both systems is inherently excellent.  Once you have enjoyed having internet access just about anywhere, you won't ever look back! 

For a more in depth look go to:  http://www.wisegeek.com/what-is-evdo.htm

For coverage maps for Sprint go to:   HERE

For coverage maps for Verizon go to:   HERE