What are the good sources for adventure ideas/plot hooks for RPG games? I am specifically not looking for purchasable, big modules which occupy a good couple of sessions just to skim through, because these take far too much spotlight and I do not want to read through few dozens of pages to scrap for anything worthwile. I want ideas which can be incorporated into any session - specific events, interesting situations, plot threads, generic things to stimulate GMs imagination. Some examples:
An important political figured is assassinated and the culprit falls into player character's mercy.
A strange person hands one of the player characters an odd, golden card which reappears in said characters pocket even if thrown away and brings the character unneeded attention of shady figures.
Things generic enough that they can fit any campaign in many settings. The source can take form of a blog, quality forum topic, pre-prepared list or a decent random generator.