I am ordering a new iPhone 4 this week and I am debating whether to get tethering along with the 2GB data plan. Here's my issue. I have a Macbook with AT&T internet service. I also have a landline with AT&T service. I was thinking of dropping both my AT&T service for my computer and landline phone and instead using AT&T to tether my new iPhone 4 and MacBook. Would this save me money? I have heard from one source that I'll probably use up my 2GB and then have to pay an additional $10 for each extra GB. So maybe tethering isn't the way to go for me. Any thoughts? Thanks ahead of time.