I used to be tethered for over a year with sprint. First day I tried I just put in sprint vision info then logged on for a couple minutes and then checked what the data charges would be. I had just a standard call plan. Data charges were high but Sprint operator suggested I add the $15 per month unlimited data plan. This worked great until about three months ago. I am no longer able to tether any more - period, so I cancelled my data plan. They said that they made some changes so that you could no longer use the "phone as modem" as they put it unless you have a plan that offers that, which are the $high dollar plans and then the phone as modem add on is $49 or $59 per month additional. Now if I try to log in the same way I always did, I get an error saying, "Registration failure, your PCS vision user name and/or password may be incorrect."