With me, its more that I simply don't use modules.
I have run 6 published adventures in 12 years of running DnD or other game systems. One of those was Tears for Twilight Hollow from a recent issue of Dungeon, which I think is one of the best I have ever read. The others are Chicago By Night for Vampire, Terrible Trouble at Tragidore because it was traditional, and the Witchfire Trilogy from Privateer Press.
one night encounters and filler pieces would help me alot, but adevntures don't fit into my campaigns very often without a serious rewrite. So, I normally just wing it. I do lift ideas very often though, for much the same things I just mentioned. If I find a great plot device, NPC or encounter I may adapt it into a game somehwere, but I rarely even think about using it wholecloth.
I really just read the modules for entertainment factor. I started my subscription fully on the merits of Polyhedron, which is funny since I was not and still am not an RPGA member.