I had a broadband data pack purchased a month ago and noticed it would expire on 25/10 but I still had 900MB unused. There is no way I can use 900MB in a day so I decied to tether my N1 and download some files to my PC. I found two files totalling 700MB I wanted, fired up my P2P client and let it rip. Thinking it would take some time I went away and did other stuff.
When I got back to my PC a few hours later I discovered that downloads had completed and I was now sharing! It seemed I had downloaded the 700MB and uploaded about 200MB (well according to the P2P client).
But on my phone were two messages from 2D I had missed. One saying I was near the allocation of my data and the other saying I had gone over and would be charged at the casual data rate. So I went online to 2D to look at how much I had gone over and found I had transferred 1.6G in that session for $72!
I have learnt a few things from this
1. 2D 3G is pretty fast and tethering the N1 is just as good as getting a USB modem!
2. Unlike VF, 2D don't automatically add another data pack to you when you go over so be very aware and don't do unattended downloads!
3. There appears to be a huge discrepency between what a P2P client says you use and what the ISP charges. Actually I see the same issue on my PC and TelstraClear's billing.
As an aside I run NetCounter on my N1 and it also said I had used 1.7G in that session.
Oh well, we live and learn.