I recently picked up a Powerbag. For those not familiar with this device, a Powerbag is a pretty normal looking case, but with a plus, a battery pack with integrated circuitry hidden inside. I grabbed the Powerbag Business Class Case (my case has the larger 6000 mAh battery, unlike this version), which offers a zip out laptop section (supposed to be TSA approved) and an internal battery. It comes outfitted with 3 plugs which are readily accessible (Apple 30-pin, microUSB and miniUSB), a port to charge the internal battery, and an extra USB slot (for "tablet" charging).
The beauty of the Powerbag is that the electronics are well hidden within the bag, offering easy access without gaudy or obnoxious cabling. As well, the bag is quite light, and reasonably well sectioned. It has a nice "tablet" sleeve which is large enough for an iPad or other 10" tablet (I fit the Microsoft Surface RT in here without much issue, and the Nexus 7 FHD slid in no problem). My 13.3" laptop fits with room to spare in the laptop section (I'd say no bigger than 15" would fit).
As someone who is carrying an extra battery pack about 90% of his life, the plugs inside the case are a great boon. I can easily just plug in my phone or tablet (Nexus 7 FHD) without having to get anything out or the like. Likewise, you can charge the bag without pulling out a ton of things (there is a nice little pocket for the A/C adapter by the plug). The Powerbag also allows you to quickly check the charge level with just one push of a button. The bag is advertised as "waterproof," but I wouldn't trust it in a rainstorm (or anything more than a light drizzle to be honest).
I would suggest that any traveling professional (or professional traveler) invest in a Powerbag. If you are always on the go, you'll find the ability to charge as you go greatly beneficial. Right now, you cannot charge your laptops, but I can envision future versions of the bags making that possible. I believe the Powerbag is one accessory that you'll find of value again and again, and it will pay for itself in convenience and ease of use time and time again.