Just about every single person I know who travels with equipment has at least a Pelican 1510 Rolling Hard Case. It's Carry-On size makes it perfect for bringing your gear onto a flight without having to risk damage or having it lost from baggage handlers.
A while back I purchased some pluck-foam inserts for my Pelican cases, but noticed I was not using them as much. Once pluck-foam is customized, you really can't make use of the hard case for an entirely new set of equipment - unless you purchase new pluck foam.
I love my Pelican cases, but they are too expensive to just be laying around and dedicated to one thing. I needed a better, easier, more modular organizing system. Of course there are padded dividers which use velcro to move around, but there's something far better out there and it's called TrekPak. Check out the video below.
So while I can't say it's cheap, the value is what you get in the long run instead of having to buy endless amounts of pluck foam. You'll most likely end up using your cases more often and the inserts are easier to reconfigure than velcro organizers. The TrekPak inserts are incredibly modular allowing you to utilize every possible inch of storage in your hard case. Right now TrekPak has complete kits available for a variety of Pelican | Storm Hard Cases. You can find a full list of TrekPak Kits available via B&H (click here).
TrekPak Hard Case Organizer Insert Kits
If you're looking for a rock solid rolling hard case to take on a flight, you gotta take a look at the Pelican 1510.
Pelican 1510 Carry On Size Roller Hard Case
Now someone mentioned about 'loose articles' floating around the bag. Don't forget you can always get cheap plastic Plano tackle boxes for small batteries and media cards, or even Padded Lens Cases to house and protect your small items like wireless receivers, cables, etc.
Padded Lens Bags for Canon Nikon Sony Pentax Panasonic DSLR Lenses