*Originally written by Io (http://us.battle.net/wow/en/character/maelstrom/io/), but I was unable to locate the thread so this is reconstructed from Google, memory and suggestions. I'll do my best to keep it updated.
An unprepared Rogue is the most vulnerable player in the game.
A Rogue's Perspective on Ganking
For 85 levels of the game, a Rogue learns to strike at the most opportune time. This often entails waiting for enemies to path away from a desired mob, or tediously tiptoeing through a cave of elites to assassinate a heavily guarded target and sap their bodyguards. Against players, the same mentality will come into play. Be wary of performing an excessive act in PvP - repeated emoting, corpse-camping or reinforcement overkill will only serve to help the Rogue remember who you are and what you did to them. -WoWwiki.com/Rogue_ganking
Blackened Worg Steak
Track Humanoids, self explanatory.
Elixir of Camouflage
Prevents anyone from tracking you on their mini-map, including Druids, Hunters and Worg Steak users.
For Druids in Cat form, etc.
Rogue's Draught (Pickpocketing)
Healing potion exclusive to Rogues.
Stealth of the Stalker (Quest)
Various items with +Stealth attributes:
Catseye Elixir (+1)
Elixir of the Searching Eye (+2)
Distilled Stalker Sight (+3, Quest)
Use to find another Rogue or Druid.
+Invisibility / Detection
Elixir of Detect Lesser Invisibility
and / or
Invisibility Field (http://www.wowhead.com/spell=84424)
Use to see invisible Mages; the latter two actually bump you into the same realm.
Living Action Potion
3 sec. immunity to slows, snares & stuns; usable while stunned. Extra trinket.
Free Action Potion
10 sec. immunity to slows, snares & stuns; not usable while stunned.
+Ranged CC / Interrupt
Embersilk Net (Tailoring)
Big Daddy (Engineering)
High-Powered Bolt Gun (Engineering)
Gnomish Poultryizer (Engineering)
Discombobulator Ray (Engineering)
Arcane Bomb (Engineering)
Frost Grenade (Engineering)
Gnomish Net-o-Matic Projector (Engineering)
The final three reportedly do not share a cooldown with the others. There are also many options for pure ranged damage, such as Hand-Mounted Pyro Rocket (Cataclysm version is "Tazik Shocker" http://www.wowhead.com/spell=82180).
Cardboard Assassin (http://www.wowhead.com/spell=84425)
Can take a pet off of you; especially useful with Vanish.
Explosive Decoy (Engineering)
Explosive Sheep (Engineering)
Self explanatory. Great fun in lowbie towns.
Send your favorite pet running to possibly divert attention from your location. Breaks stealth.
Blue Smoke Flare
Green Smoke Flare
Purple Smoke Flare
Red Smoke Flare
White Smoke Flare
Can be thrown from stealth!
Rogues Deck (Quest)
Archmage Vargoth's Staff (Quest)
Highborne Soul Mirror (Archaeology)
These will summon a semi-transparent stationary unit that may distract your opponent. Useful with a Vanish or to divert attention while already stealthed. The mirror creates a replica of your character, but it will face your direction, possibly giving away your location.
Lure your opponents into a false sense of safety. Amass a critter army, stealth, profit.