SMBC: PuCube

Source - SMBC

See, it's funny because plutonium kind of would do all those things (as Randall Munroe pointed out previously).

Working downward from the top...

• The plutonium would give off energy for way more than just "2+ generations", and it would heat the tea around it. From Randall's calculations, though, it seems like it would keep the tea warm but not hot.
• Plutonium in water would emit Chernekov radiation which glows a very pleasing blue.
• 1.5 cubic centimeters of plutonium would certainly fit in your pocket. It would be about 1.14 cm on each side of the cube. 
• The plutonium would certainly sterilize your tea for you...if that's a problem you normally have with your tea.
• You likely would get to meet your local FBI agent - possibly an IAEA agent.
• You should not swallow PuCube. To get an idea of what could happen, read about this former Soviet spy poisoned via polonium.
• As to the $400,000 cost, the only reliable sources I could find put the price of plutonium between $4000 and $6000 per gram (though I prefer this answer). 1.5 cubic centimeters at 19.84 grams per cubic centimeter at $5000 (an average) per gram, that would be closer to $150,000. My math doesn't jibe with Zach's. I'd need to see his sources.
• PuCube certainly would be heavier than you would expect. 1.5 cubic centimeters of water (a fairly dense material) would have a mass of 1.5 g (at 4 degrees Celsius, natch). Osmium and iridium would be the most dense (at 22.6 and 22.4 g/mL respectively - source), but I'm guessing the plutonium would be much heavier than you would expect. I've picked up mercury (13.546 g/mL compared to plutonium's 19.84 g/ml), and it was surprisingly heavy.
• The repeated warning not to swallow PuCube make me think of Happy Fun Ball. Do not taunt PuCube.

And the rollover joke...

See, because americium is radioactive, too.