ONE OF THE new features we had expected to be added to the MacBook Pros is a built-in cellular modem so that we don't have to carry around USB dongles wherever we go. Maybe Apple reason that the new iPhone tethering will avoid the need to add a modem and the cost of modifying the aluminium cases to accept a SIM-card slot. Tethering, though, isn't a complete answer and is unlikely to work out cheaper than having a separate USB modem. At the moment, in the UK, you can get a monthly 3GB of data on a cellular contract for between £10 and £15. First indications are that O2 will be charging iPhone contracted users an extra £15 for tethering.
On this basis, we would sooner have a separate contract for data because tethering does bring some disadvantages. It drains the phone's battery if used via bluetooth, so most users will opt to connect the phone to the laptop by cable. And we know from past tethering experiences (with Windows Mobile) that using data and making phone calls at the same time can be awkward and prone to difficulties. Maybe the iPhone implementation will have no such problems, but there is certainly no financial incentive for the owner of a current data contract to close it down and use tethering instead.
So, despite the advent of tethering, we think a built-in cellular modem for MacBook Pros will arrive within the next year.
iPhone users who choose the tethering bolt-on will need to be super aware of the costs when travelling abroad. It's bad enough to roam with an iPhone, but the data clocks up relatively slowly and only becomes a real problem if you're downloading uTube or other video material. With a tethered PC, though, it is quite easy to rack up a gigabyte of download in a very short time. And that can bring a bill of at least £3,000 if travelling in Europe or £6,000 in the USA. Some cellular networks will charge up to £10,000 per gigabyte even within Europe. Bad news.