I never understood everyone harping on SparkFun for making this cable.
Yes, it doesn't work with everything. Yes, it goes against the USB standards. (The non-hub version, anyway - which you can actually kinda-sorta fix by capping the unused ends with bus-terminating sockets)
But who cares? It works for power, which is what it's going to be used for 95% of the time anyway - and putting an unpowered hub in it limits power output per port which kind of ruins the point. (imo, the hub version should have 2 USB A male sockets to allow for additional power, but oh well.)
And if you're the special kind of person who's going to try to plug two things into it at the same time, you deserve all you get...
I'm disappointed that this one doesn't also break out the data lines in a pair of alligator clips...
I don't know about you, but I know most people who are just starting to get into electronics (i.e. I BOUGHT AN ARDUINO EXPERIMENTER KIT NOW WHAT) probably don't have a bench power supply of any kind.
A computer provides a relatively stable 5v/0.5-3a (depending on USB version and port configuration) supply with overvoltage and overcurrent protection, what's wrong with a cable that breaks that out into something more useful? I'm sure I'm not the only one here who's chopped a USB cable up to tap the power wires out to spade/banana/alligator connections.