I seem to be enamored with portable chargers lately.
In the States, keeping my phone charged was never really an issue; I charged my phone when I went to bed and it was enough for whatever I did for the day. I do the same here, but with all my train downtime, mobile games and useful apps (including the ones I use to write entries) tax my battery much more. There have even been a few times I’ve almost run out of juice.
Enter the portable charger. You can get a simple one at the store — even a convenience store — but game centers have much cooler ones, and for roughly the same price. I have compact models that slide easily into a pocket or bag, as well as one with four ports and an LED light and one with a three-setting flashlight (high, low, strobe). Any time I’m going to be out for a while, I take a charger with me. They make good gifts, too.
(A word of warning: They tend to get pretty hot while working, so be careful when charging devices.)