Alex, do you have any pictures of the wooden "cell" towers?

That's the idea, Kev. There is also a well-developed trade of people who have a phone and rent it to those who do not, but the really clever stuff begins once you get more handsets out there. In the DR Congo, some communities have built wooden towers so as to climb high enough to get line-of-sight to a cellsite that would otherwise be out of range.

Now there are GSM handsets that cost less than $30 to produce, though, airtime sales are likely to predominate. African GSM operators are really creative - I mean, Nokia, T-Mobile, NTT, and others spent kajillions and years trying to design a secure, instant, interworking mobile payments system in Europe, and failed, but these people realised that, as an airtime credit is really just a unique ID number to be fed into the BSS-OSS prepaid management software, you could send it as an SMS message.

I didn't realize that, Alex. So you bring your own phone and just purchase air time?

The bottom picture at Lake victoria is brilliant. Can I download it somewhere in a higher resolution?

Did you know that Lake Victoria is as big as Ireland?

The first one isn't actually a phone booth but a stall selling GSM pre-paid airtime credits. In large parts of the developing world, these are becoming a form of currency, as they are transferable by SMS messaging. If you want to send money home, you buy X amount of extra minutes, then text whoever you want to send it to with the transfer code.

It has the great advantage that it's instant, secure (can't be intercepted or stolen), and not subject to bribery and rent-seeking. The recipient can either use it, or else transfer it to someone else in exchange for goods or services - or for that matter transfer it to someone else in exchange for cash.