Missions & Complexes

IIRC red cans used to drop faction stuff

Integrated and augmented drones have to be among the least useful items on eve. that and midslot batteries.

Leaking Casks - saw them often in Haunted Yard (Hisec) and Dirty Yard (LowSec) Sites. Description: red colored containers. Never found anything in them so far, might be there can be something inside
http://wiki.eveonline.com/en/wiki/Haunted_Yard

Scratched Casks and Black Drone containers - u will find them in Rogue Drone Asteroid Infestation (3/10), a very common highsec plex. Both drop Overseer tags, scratched casks may drop faction. Found some faction loot more than once in scratched casks, never found faction loot in black drone containers so far
http://wiki.eveonline.com/en/wiki/Rogue_Drone_Asteroid_Infestation

In those complexes you may trigger a drone with "Sentient" in its name. That drone drops drone loot needed for the production of more effective player used drones. By salvaging the wrecks of "Sentient"s you may get t2 salvage also.

Then and when those complexes trigger a so called escalation. You will notice a message window popping up upon completion or elimination of commanders (to which sentients count also). Information about that you can find in your logbook under "expedtions". Those escalations may lead you to further "sentients" and are fairly easy. Mind that depending on your autopilots settings and factions an escalation can lead you to far distance travelling and will relatively secure lead you to Lowsec at the end. Better read about the escalation you have triggered in the spoilers.

As a general rule of thumb you can assume, that the higher the complex you have been in, the higher - and more difficult - the expedition will be. In highsec the most valuable expeditions are triggered in 4/10 rated sites. Be careful though, since ressources in the net do by far not tell you the true facts about the higher escalations. In fact those are one the few unrevealed secrets within Eve, and those who are ware about them keep them secret. Examples are delayed triggers and escalations in the escalation leading to a however different result or story of a certain expedition.