I recently dusted-off one of my old houserules. It was created for 2e AD&D but it translates easily to 3.x or even 5e D&D (probably 4e D&D too, but I never tried).
This houserule aims at offering a quick and dirty way to track encumbrance. So if you are on the fence between keeping track of your player's stuff and viewing encumbrance as a waste of time and efforts (or if like me you are playing with young-ish kids), this houserule might interest you.
In a nutshell, forget about weight in lbs; objects have burden. Carried objects' burden add-up to determine the character's load. As long as a character's load is equal or inferior to its Strength score, the character has light encumbrance. If the character's load is superior to the character's Strength score but equal or under its STR x2, it has medium encumbrance (reduced speed, max dex bonus to AC of +3 and skill check penalty of -3). If the character's load is superior to the character's Strength score x2, it has heavy encumbrance (reduced speed, max dex bonus to AC of +1 and skill check penalty of -6).
Normal clothing and small objects (such as a dagger, a potion or a single arrow) have negligible burden; a character can carry as many such items as sensibly possible. As a rule of thumb, items with a listed weight of 1 lb. or less in the core rulebook do not have a burden rating.
Armors are the most burdensome items typically carried by adventurers. A suit of armor has a burden rating equal to its armor bonus to AC. Armor properties or character abilities that lessens an armor's skill check penalty reduces the armor's burden by an equal amount.
Most other adventuring gear has a burden rating of 1 or 2. Most one-handed weapons, light shields and other manageable items (such as a blanket or a bedroll, a wizard's spellbook or a waterskin) have a burden rating of 1.
Two-handed weapons, heavy shields and weapons (such as a heavy shield, a heavy flail or a heavy crossbow) and other cumbersome objects have a burden rating of 2. The definition of "cumbersome objects" is left intentionally vague but if a line has to be drawn, items with a listed weight of 10 lbs or more (such as a sledge hammer, 50 ft. of hemp rope or a two-person tent) are considered cumbersome.
Items sold or carried in bulk (such as 7 days worth of rations, 10 torches, 20 arrows, 100 coins) have a burden rating of 1 per bundle. A half-used bundle conserves its burden even though it should logically be lighter; this represents the growing weariness of the adventurer compensating for the loss of weight.
When calculating burden, do not include the weight of bags and backpacks. In this philosophy, the backpack is an extension of the character’s ability to carry things more than an object in it own right. If players insist on carrying large chests and heavy barrels, just tell them that they can't fight with those in hand.
'findel