Jon brings up an interesting point with reference to the curling iron and hair dryer.  I have taken some newbies with me and have been surprised with what they have brought.  One guy brought 3 full rolls of duct tape which were in addition to the small roll of duct tape that I brought.  I have considered unpacking everyone's pack and checking what they have in it.  Something similar to what they do at the airport.  I haven't done it yet due to a concern about privacy, but I am seriously considering doing it in the future.    Some packs I know aren't packed correctly because they are just too light for the size of the pack.  In other words, they have a lot of air in their packs.