"The players are there to keep the referee amused. If they don’t, he will find a way to make it entertaining."

-Dave Arneson.

The players have just spent 15 minutes discussing the minutia of an ill-fated scheme, and you're like "oh come on already!' choose or make them roll a relation ship die to move the game on - here's some Icon related ideas, as you use them think of new ones for next time.

Liche King

•  A spectral apparition hints at danger.
•  You sense an evil magic user scrying your thoughts.
•  Gravefrost spreads across every surface.
•  The dead rise.
•  A talking crow brings ill news.
•  The place they're in sinks into the shadow fell.

Archmage

• An influx of magical energy permeates through the area, re-organising its layout.
• The doors and exits are transformed into planar portals.
• Surplus magical energy ignites creating swarms of fire elementals.
• The veil of night is pulled across the world.
• A wizard reeling from smoking wounds collapses in front of the players.
• A living spell is born, angry and confused.

Emperor

• Two powerful dragons duel in the sky, the loser tumbling out of sight.
• An empire courtier appears, badly wounded and almost unconcious.
• A passing bureaucrat and his retinue demands the characters show him reverence.
• A pair of loud overweight squabbling nobles can be heard as their disagreement turns physical.
• The secret police mistake a Character as a wanted enemy of the state.
• Two dozen guards begin breaking down doors and begin hurriedly searching for something.

Prince of Shadows

• Whispering and the rough sounds of a struggle can be heard coming from a storm drain.
• An amiable assassin mistakes a Character for his mark, and attempts to carry out the contract.
• An influx of cheap golden lotus seeds floods the market, causing gangs to fight bitterly over its control.
• The characters are pick-pocketed, only to find the thief face down dead.
• A beautiful daughter of a wealthy merchant seeks sanctuary in the underworld.
• Swarms of rats begin to pour out from every drain, hole and conceivable space.

Orc Lord

• An eclipse occurs, signalling an Orcish festival of bloodshed.
• Several wildmen encounter the characters whilst hunting.
• The savage tattoo of tribal drumming is noticed and gets louder and louder.
• A shaman appears to the characters in his spirit form seeking their council.
• Smoke rises on the horizon, an orcish warparty has sacked a local settlement
• The players find a hideous totem laden with fresh sacrifices.

Priestess

• The players are heckled and jeered for being blasphemers and non believers.
• Road-weary and Pilgrims pass by offering alms and prayers to the faithful in need.
• A distant bell tolls, announcing a religious period of atonement.
• A holy spirit gives visitation judging all present.
• The characters find a truly ancient text of verses, hymns and prayers trapped within is a disquieted soul.
• Heavy rain and a flood of biblical proportions threatens to sweep the land clean.

Diabolist

• A small, fat demon, falls from its hiding spot – it appears to have been following the characters for some time.
• The heavy influence of the far realms begins to twist and bend space and the laws of physics.
• A small child appears, with a deep and guttural voice it intones a dire warning, pointing at a character.
• Droning and unintelligible speech of several voices fills the air, ever rising in volume.
• An unholy altar bursts through the earth surface, faint chaotic runes let of an eery glow.
• All inanimate objects suddenly begin to laugh and dance wickedly, only to stop a quickly as they began.

Dwarven King

• Someone calls attention to the fact that all the players coinage is part of an ancient dwarven hoard.
• A book of grudges is produced, one of the characters ancestors is in it.
• The hubbub of angry striking miners can be heard, demanding better pay and greater share of wealth.
• The dwarven masonry begins to crack and crumble, so much for a lifetime guarantee.
• Everyone is required to take part in a long and difficult drinking game, lest someone be deeply offended.
• Someone called someone else's honour into question, and no one leaves until the culprit is found.

The Three

• Two volcanic dragons eggs tumble from a rocky slope, resting at the characters feet.
• A mated pair of Chromatic dragons demand the local populace give up the PC's
• Chromatic dragons underlings fight a fleeing young half breed dragon with exotic magical apparatus.
• A small golden box, with delicate inlaid dragons falls from a rapidly moving cart amongst a busy throng. 
• Twinned magical mirrors reveal a glimpse into a Chromatic dragons conversation with his vassal.
• A pugnacious and badly wounded adventuring party seek aid, they say their comrades have been slain by dragons.

Gold Wyrm

• A gravely wounded Metallic dragon has polymorphed itself into a coin that one of the PC's in possession of.
• In the distant skies the glinting of hundreds of metallic dragons, convening an ancient wyrm court can be seen.
• The PC's overhear the drunken boasting of thieves claiming to have raided a Paladium Dragons hoard.
• Worshippers of the Gold Wyrm clog the streets, chanting and ringing bells.
• A young metallic dragons seeks out an audience among the PC's hoping to inspire both fear and admiration.
• Through a small land slide the ruins of an ancient Wyrm bastion are partly revealed.

Crusader

• The local witch finder is asking questions about the PC's and their associates.
• A rusted iron gibbot, its most recent occupant hold a delicate piece of parchment in a withered fist.
• Some haphazard thieves flee in a state of panic and terror, a masked vigilante hunts them.
• A well respected, yet secretly evil local sorcerer is found dead much to the outrage of the locals.
• The brash sounds of labourers can be heard, they appear to be erecting a wooden stage, complete with trapdoor.
• Several manic agitators begin stirring up resentment and hatred in plaza nearby.

Elf Queen

• Members of the Fey court come across the PC's during the courts progression.
• A raven appears with a delicately written summons, calling PC's to give evidence at the Fey court.
• Elven supporters end up worse for wear after a heated encounter with another icons followers/agents.
• The PC's discover a secret door in a tree, leading to an ancient barrow beneath the earth.
• By public proclamation an elven blade singer stands accused of unearthly crimes, and a great bounty is set upon his head.
• The players find a rare seed from a Life Tree.

As you can see some if not most of these refer to intentionally vague or implied pieces of story/game lore. The purpose is to make them your own, and weave them into whatever story you've got going on - or to help kick start a new romp.

Enjoy - and if you have any more, please post them into the comments i'll happily update this post with them.