Nowadays this circuit is inefficient and will not charge smartphones. It is better to use step-up regulators in order to achieve good efficiency and charging current.
To make this you will have:
LM7805 (voltage regulator) cost: 70 cents
dual USB port cost: about one dollar
9V battery connector cost: nothing! (i have got this from 9V battery)
and hmmm... thats it!
you must have soldering iron and solder of course.
Solder everything tohether using tips from picture 2.
And thats all!
You've got it!
Dual port USB charger!
Thanks for vieving!
(don't forget to rate!)