Wow. This thread has kept me in the bathroom longer than I expected this morning.

Ayways, I've read quite a few people on here mention that more people would pay for tethering if the pricing allotted for smaller chunks of data, such as "why pay $20 for 2 gigabytes when I'm only tethering 500 megabytes?"
I actually brought this up with a Verizon tech way back right before the official Froyo was pushed out. I was asking about the new usb tethering option and what I was told was yes, first you had to sign up for it, but you could also take it off your account at anytime and only get charged a prorated amount.
Meaning, if you were visiting your sister for the weekend and she lived somewhere without internet access, then you could call up Friday evening before you left and add tethering to your account. Use it for the weekend, and then Monday call and take it off, then when the bill came in at the end of the month, you would only be charged for what you consumed at whatever the going rate is.
Now this has nothing to do with the morality of tethering or thew TOS os anything else. I just wanted to pass this info forward to those who expressed concerns about paying for 2gigs and using less.
Granted, this conversation between Verizon and I was a while back, but I haven't seen anything in their plan changes that would affect this (Assuming the support tech I talked to was correct).
I don't currently own a computer because with my lifestyle, my smartphone has become my personal computer. But, In still have the Wireless and Wired tethering apps installed because when my fiance brings her laptop over and needs to do her schoolwork (she attends university online), then I can just turn it on and let her work while I lay in bed and do my own thing at night. Am I breaking my TOS? Hell yeah. If Verizon wants to terminate my service then go for it, but I'm pretty sure that with the amount of data I consume my head isn't that high up on the chopping block.
Correct me if I'm wrong, but when you tether "legitimately" doesn't your phone access data using a seperate .. um.. well domain (not 100% on the tech side of things because I haven't read much into) That's how Verizon can track and bill your usage. All tethered data goes through (for example) myphone.tether instead of just myphone.data. These domains are hardcoded in your phone's VRAM and when you boot your phone they are loaded into memory. There is a hack available for the Droid X/Droid 2 (search mydroidworld) which you can flash which will change the domain used for tethering, so you can effectively tether using the built in app and not be redirected to the Verizon site which asks you to register. My terminology may not be spot as I'm no expert in this field.
Now how third party apps work, I have no clue. Since Android is open source based I don't even know if they even attempt to hide the fact that you are tethering considering that that isn't any concern to them, nor have I read any claim stating that by using their apps, the fact that you are tethering will be hidden.
But Verizon isn't stupid and don't have to resort to checking packets, etc. to get their point across. They most certainly know typical and atypical usage patterns. Using a set of equations, they could failrly easily come up with a list of suspected tetherers and send a C&D letter much like AT&T did with iPhone users. Also keep in mind, AT&T, last I read, did not have any method of identifying tetherers. They sent this letter to users with high bandwith usage or to those that matched typical tethering patterns. AT&T hoped that everyone tethering would have been scared enough to either stop or to call in and have the tethering plan attached to their account.
Anyways, back t what I was saying. Verizon knows how much bandwith a smartphone can max out per month. If you exceed this, then you are most likely tethering (most likely sharing your connection). Smartphone users are also fairly predictable and obviously the more you tether the more you stand out. Different equations can be created using this principle. Hopefully everyone gets where I'm headed with this because I don't need to teach statistics this morning.
Once Verizon has their suspected tetherers, out wll come the letters much like AT&T. No definitive proof at this point, but they hope to scare enough people into buying the service. Possibly those people that they know for a fact ar tethering (those using more bandwith per month then possible) will have the package added to their account.
What scares me though is if Google let's the carriers have the same level of control over our phones that they do. Then all Verizon (or any carrier for that matter) would have to do is remotely uninstall any tethering app from "infected" phones periodically. I don't see this ever happening though.