We acquired two 20 watt portable solar panels, both being the Anker PowerPort Solar. We use these in conjunction with two 20,000mAh power banks, each being the EasyAcc Monster 20000. The EasyAcc battery packs have dual ten watt USB inputs allowing them to charge at up to 20 watts which means in full sun light the solar units will charge each battery pack at wall outlet speeds. When in good sun light and the opportunity arises I whip out one or both solar chargers and store some rays in the battery packs or, sometimes, charge a phone or two directly.
The solar units are small, light weight yet sturdy. The only issue I've encountered is overheating charging devices. The solar chargers have a small pocket for storing devices while being charged, but in the sun this pocket heats up real quick. I recommend propping up the solar panels and placing charging devices in the shadow of the panels. I have a folding laptop desk that I often use as a stand for the solar unit which allows me to better angle the panels to get the best out of the panels.
In addition to the power banks we acquired a AA/AAA battery charger that charges from USB so we can also charge the batteries for our flashlights, bicycle headlamps/taillamps and wireless input devices with solar energy. The caveat here is that it will only charge batteries in even numbers, 2 or 4, and some of our devices use 3 batteries. Because of this it's useful to have more batteries than you need. When three batteries run dry charge two of them and replace them in the device with another fully charged battery and keep the third discharged battery somewhere until another odd number of batteries run dry then you'll have an even number of batteries that need charging.
We also have a BioLite campstove which is a rather nifty little device that cooks your food while doubling as a mobile charge station. For cooking food this thing is great, it burns twigs which are free and common, and charges a built-in lithium battery from the flame. The built-in battery powers a little fan that pushes air around the flame, fueling it and creating an upward vortex to direct heat toward the cooking area, but also can carry enough charge to deliver power to USB devices such as mobile phones and tablets. It would take much longer and more effort to fully charge a device when compared to the solar chargers so I would use this as a backup plan in low light conditions, though I'd imagine it'll take a good deal of wood to charge a device.