To be fair, you can easily carry around 2 TB in a single large-form external. Coupled with a general car to wall AC adaptor, you can travel around town with it.

Not to mention the fact that since it's just a simple look-up table with lots of small entries, you could store it in the cloud and only get what you need via the same GSM connection.

That's a lot of data to be uploading to the cloud, but I read you.

I wasn't saying it wasn't doable, but rather it's not just as easy as grabbing your laptop and a $15 phone, which is how it's being reported, for the most part.

You can send a USB or eSATA external drive to Amazon (up to 8TB) and they'll import the data into S3 for you. http://aws.amazon.com/importexport/

This is great, I didn't know about this. It's important to note that you're looking at a cost of $100+ when you factor in Amazon's fees and shipping.

Actually, four cheap phones (4x Motorola C123) have been used, operating in parallel. :-)

And they have furthermore been modified to remove filters that in "normal" phones improve signal reception but for this particular application would prohibit you from listening to the base-station-to-phone direction.

Yes, 4 ... but the number is not really important, mostly depends on the activity of the cell. Also my code is currently highly sub obptimal (I use 1 entire phone to listent to 1 control channel ... in theory a single phone could dump 32 of them at once).

And only one single of those was modified (the one used to dump the traffic/voice channel, the other only listen to the BTS)