Tubes..I'd only do vertical..but they could have shorter sections horizontally..say a 2/3rds bottom area and 1/3rd top with zips around at those points or vertical zips or velcro..for shorter tube section so you don't have to dig to the bottom of one long one.As far as diameters..a person could make 4",6",and 8" diameter tubes to carry most stuff they need.Again..pockets outside can carry smaller stuff that gets lost.One of the main ideas is to eliminate a lot of sorting,packing,and unpacking..before and after a trip by segregating the items you need into separate areas.My golite packs have several pockets for small stuff..mesh ones to see through..that contain or carry most smaller items.They also have no internal support so I roll a foam pad around the inside perimeter..ease it out to the full diameter,then stuff the larger items inside the rolled pad..and saving the weight of "pack padding or internal supports..but I always am 25lbs or less for everything including food and water.
I don't usually use tent poles because I use my trekking poles for them..so I really don't need a full length one unless I want to stuff a tent or hammock skinnier in a long one..say wrapped around 3-4 beers..
I think horizontal tubes might be an option..use ties and push button cord lock all on the same end..but that might screw up ideas for pockets on the outside..unless they also have some kind closures,velcro,cordlocks,etc..
Bear cans are a pita,guaranteed to screw up a back if carried without adequate padding..especially because they make the diameters large enough a bear can't get his mouth wide enough to crush them.I usually use a golite race or speed packs(2lbs each) and add a special mesh bag I can lay across under the hood or strap the mesh bag on(tie-on spots added to the outside of the bag).The damn cans do not have any or adequate ties on them.The little bumps they have on some of them I wouldn't trust to hold a strap between them and would expect to see a bear can rolling all the way back down the switchbacks you just climbed..or over a cliff somewhere,impossible to get back..no thanks.
I only use the legal manufactured bear cans in the upper mountainous region of Olympic National Park($3 refundable fee..or donation,your choice..per can/ trip..why buy one).On the ONP coastal beaches I can use aluminum(or stainless)dairy farm cream containers in optional sizes(1-4qt..have 3-4 sizes..think one might even be 5 gal!) with bail type handles and screw on lid.The diameters are smaller but the beach areas only have raccoons and possums as pest problems so the rangers have approved them for me there.Most of the local areas around Seattle..don't seem to need "required bear containers"..a lot of places have hang wires(noted at websites)..so a person can prepare appropriately for the trip.I add a bolt and wing nut through the screw on lid area(or slide in),a couple caribiners,and about 40' of line wrapped around the can..I can hook the bail to the back of a pack and strap the rest with a strap through the equipment strap loops on the back.Golite packs lack strapping per se on the back..but both of mine have "helmet" mesh areas that will hold the cans.My smaller 1lb pack I've added straps to tie stuff on the outside.
Keep in mind that I can also use the metal cans for boiling larger amounts of water..where you can't do that with a plastic or kevlar bearcan...
I think I've seen some of the metal cans in the larger oriental stores...but have found all mine for $2-5 each at the local thrift stores here.The smaller diameters make them also easy to get into smaller packs with just clothing as padding between the back and the can.I think I probably have 4,5,and 6" diameter ones..about 10-14" high.http://s226.photobucket.com/user/realit ... sort=4&o=6