Wandering Monsters

From http://www.enworld.org/forum/general-rpg-discussion/294548-has-wandering-monster-concept-died.html

Published modules in 3e and 4e often don't use them, yup.  This leads to modules which are incredibly static as written and encourage the 5-minute-day - go in, do 1 encounter, rest, do the next, etc.
Personally I will always use the possibility of wandrering monsters, especially if the PCs are spending a long time in the dungeon.  If necessary I'll roll to see if 'static' monsters in nearby locations come wandering by, which can be as much a benefit as a detriment to the PCs.
Running a sandbox wilderness I don't know where or when the PCs will go, so wandering/random monster encounters are a vital GMing tool.  But for 4e, rather than a huge d% monster table, I'll often pregenerate a small number of detailed monster encounter groups and use one of those when a random encounter is rolled.  
Even with 1e, depending on the complexity of the tables I may often roll up several wandering/monsters prior to the session which I can use as appropriate, this helps prevent me being wrongfooted by something in the session I'm not prepped for.  Eg running City State of the Invincible Overlord, the city encounter tables are very complex, and can be hard to use 'cold' in play, whereas a simple d12 dungeon wandering monster table can easily be used ad hoc.