As much as I'm anti-Apple, the iPhone (like almost any not-too-basic phone) is supposed to be tetherable :
http://www.apple.com/iphone/how-to/i...one-as-a-modem
You can also tether the N900 with USB networking or bluetooth, it's just more complicated.

Nice story, though, I'm sure the Joikuspot guys would love to hear it.