Many of the airlines I HAVE to fly on (LCCs only to where much of my family lives) won't allow a personal item in addition to a carry on.

I've become an evangelical convert to packing cubes and LOVE the Zuca pro system (which is too large for those airlines with a maximum of 20x40x55cm for carry on, but for this the Zuca Artist back pack comes into play). You don't actually need a Zuca case to stack packing cubes, there are tons of messenger bags and make up bags and photography bags that will let you stack them.

I like the Zuca packing cubes but I ADORE the Glamcor utility pouches which are so similar in size as to be compatible with the large Zuca cubes. They are much sturdier than the Eagle Creek example you demonstrated.

The reason I am bringing this up is to convey my own strategy for one bag carry on rules, particularly if travelling with a zuca pro and the weight limit comes into place:

To solve this issue, remove 1 or 2 of your packing cubes from your luggage and wear them rather than carry them. I fixed my own vest with two internal pockets (I can't sew for toffee but this was simple) the packing cubes just slide into the pockets. They stow under the seat with my vest and coat and it's simple to just slide them back into my luggage once I'm on the move again. If you don't fancy sewing there are any number of vests and coats on the market that will take the packing cubes.

The large Eagle creek cube isn't ideal, at 36x25x10cm it is wider than the 23cm max many flag carriers now have as a limit and so won't stack easily in the way I'm suggesting, but the smaller pack-it cube is a good size.

The large standard Zuca pouches (which you can buy individually) are L 29cm x W 21cm x D 7.5cm - so will stack nicely even in the 20x40x55cm LCC cases and the Glamcor cases are pretty much the same dimensions.

So, for those who need to travel within the 20x40x55cm limitations - which may or may not have an 8kg or 10kg limit, this is my solution:

I am currently adapting a Zuca Artist backpack (which weighs 1.5 kgs) by adding some loops so that I can attach a customised shoe case (the large Eagle Creek shoe cube, sadly out of stock, is absolutely ideal for this) with loop-around velcro straps. This will extend the Zuca Artist Backpack from 39cm height to the maximum height allowed; 55cm and so allow me to fully utilise my allowance whilst remaining organised throughout my trip.

http://www.zuca.com/control/product/...egory_id=10010
Zuca Artist Backpack comes with two small travel cubes. Each additional costs me £10. Four cubes fit into the backpack and the additional shoe cube (36x20x15cm) is roomy enough for items that won't fit into the smaller cubes. If weight is an issue, one or two smaller packing cubes are removed and worn for a short amount of time.

(Note that the cubes for the Artist Backpack are slightly smaller than the larger Zuca cubes and glamcor pouches, you can squeeze them in, but it just isn't as elegant)