Here, for example, are two mobile broadband dongles from O2 (left) and BT (click here to read about BT’s new mobile broadband service). One causes me endless hassle on the train journey into work of a morning, while the other is painless. The difference? That little white piece of string that keeps the BT dongle’s cap connected to its body. 

Something as innocuous as a cap retainer might sound utterly trivial, but I’ve lost count of the amount of times I’ve ended up on my hands and knees, picking my way through the half-eaten bag of Doritos and discarded newspapers under the train table, trying to find the AWOL O2 cap. It doesn’t even fit on the other end of the stick!

The BT cap, meanwhile, remains firmly anchored to the stick, no matter how many hard-disk threatening bumps the train encounters.  How much does that little piece of string add to the cost of the device? A tiny fraction of sod all. How much difference does it my mobile broadband “experience”? A pretty sizeable one.