Ferrofluid is a spooky looking substance that reacts to magnetic fields in really cool ways, and the fact that you can make it at home means everybody can experience the joy of owning their very own Venom Symbiote!
Okay, so ferrofluid isn't quite as cool as a Symbiote, and it won't destroy your entire town if it gets out, but as the CrazyRussianHacker discovered ferrofluid in a tube full of clear liquid makes for a pretty cool lava lamp.
Here's more info on this scientificool piece of home decor by Inspired Designs called "The Inspiration":
A 450 mL glass Ferrofluid Motion Lamp with 15 mL of ferrofluid inside. Largest ferrofluid display on the market. Built to last. Patent Pending technology. Yes, The Inspiration also doubles as a motion lamp with rising blobs. The ferrofluid rises/falls on its own when the lamp is turned on, in the same manner as the famous lava lamp. Includes magnets.
-Via Geeks Are Sexy