In today's world we have many different options for internet connectivity.  Some are good, others not so much.  It can be a hard decision to find which one suits your perfectly.  This is where, for some, the option of EVDO comes in.  EVDO is a very mobile version of broadband internet, this is a huge perk as you can take it wherever you go.  As with other internet service providers, you have to pay a monthly fee, and you must buy a product with EVDO capabilities.   In my experience both Sprint and Verizon have speedy and reliable connections.  Although location can drastically effect your speed, you can expect speeds of 600kbps-1400kbps download and 500kbps-800kbps in an area with decent to exceptional coverage (this is based on the "Rev A" capable models")

      EVDO is available via "data cards" from most cellular providers.  These cards can connect to your computer in a number of ways, however the usual form is USB.  I recommend the USB cards, any respectable modern computer is equipped with multiple USB ports. 

     In addition, you can find numerous accessories to fit your own personal needs.  There are many wireless routers that cater specifically to these data cards.  With these routers you can take your internet with you anywhere, wireless!  Many of them include battery operation, as well as ac and dc capabilities.  Aside from the routers you can also find antennas specific to your card, for those who do not have decent reception (or just want to make it better).

      Over-all i would recommend this as a secondary internet connection.  It is portable and is capable of respectably fast speeds.  Just make sure you check availability in your area of operation before you choose a plan.