This sounds like an interesting idea, something I've had in the back of my mind for a long while except that I was thinking of using WiFi as there's a network everywhere here at uni.
What exactly do you mean when you say it fits perfectly in the slot? How much does it stick out?
Not at all - i.e. it's the same size as a CF storage card.
For the system to be effective for me, I'd really need it to be on and idling, always ready to receive data.
Really? What will you be doing with it that you require such fast updates? I would be quite happy to carry out messaging more slowly (like sending emails, etc.), though it you're also wanting to utilise some form of location awareness then you're probably going to want to have the Z switch on more often as your location/context is changing more rapidly.
I'm not sure how to balance this need and that of saving the battery, but a challenge is always good
In any case I can't really see why the Z couldn't switch on every 1 or 2 minutes, connect to the phone and check for messages/email/whatever, then go back to sleep. I suppose that if the phone could also ascertain it's current location it could then decide how long to sleep for depending on what it expects it might find, etc.
I'd be interested to know what the battery life expectations are with the screen turned off, as well as how much of a power drain using BT (or WiFi) would be, and also how long it takes to obtain a connection - as you'll want to balance the number of sleep (and subsequent connection) cycles against the time (read power) wasted being switched on with BT powered up, but not doing anything useful, just negotiating with the phone, etc.
Si
