Nothing so creative. WECL in SSP carries a shell that takes 18650 Li rechargables and outputs enough current to charge a smartphone. So it's like a much larger than usual Lipo battery pack. The only advantage is that you can reuse the cells for other things (which I do).
Those Powerbank units look quite nice. Not really for me though- they look a bit fragile for Lipos. The upside of 18650s is that they are Li ions so less likely to catch fire and I don't worry about them as much.
I am fairly wary of any lithum-based rechargeable chemistry. I've had >50% of my cheap Chinese Li ions packs go bad, including what I had (probably incorrectly) assumed were Sanyos from SSP.