The really interesting aspects of the deal
Given the historically local nature of mobile networks in the US tie-ups and buyouts of this nature are inevitable over time. Rolling out real ocean-to-ocean coverage in the US akin to that required in Europe is time-consuming and extremely expensive. Are there any maps that show how the various networks are represented in the US? At least the move to a single standard (GSM) allows to them provide roaming services to their customers in areas where they don't have masts.
Buying a much smaller operator will not provide much in the way of synergies and it won't save the operator any roaming charges as these are paid (with interest) by the customer but it improves T-Mobile's coverage and brand recognition in an important area. Don't know how much tourist trade they can expect to pick up (and profit from) but this might have been a major motivator.
In comparison to deals by other international networks (Telefonica, Vodafone and China Mobile) it's small scale but it is in the one market that is providing significant growth for T-Mobile with Germany, the UK and the Netherlands saturated. Having paid for Voicestream in cash at the height of the mobile boom, T-Mobile doesn't have the readies for integrating large networks in developing countries with expanding markets but is funding the acquisition by the cash generated by it's US network and while that doesn't make it as big as AT&T or Verizon, margins are often more important than market share.
Apart from the back: let's get back to the sniggering!