Verizon $44.99 PDA/Smartphone/BlackBerry Unlimited Data.
That's not tethering. It's the $45 data plan you put on a PDA phone to do corporate e-mail in addition to personal e-mail and Internet on the phone. It's always been unlimited.
If you have this plan, tethering is an extra $15, and it still has a 5GB ceiling for data with overages if you surpass it. Tethering and on-screen data are separate fees with different limits.