HA! That's the same thing I initially thought about.
Measured against interstellar space, each of us are moving at least 1,300,000 mph, just sitting at our desktops.
Where did you get that number? I actually tried some back-of-the-envelope calculations the other day, and could only really give approximations about rotation speed (approximately 1000 mph), and orbital speed, which was quite a bit more. My numbers on the galactic orbital speed was really too fuzzy to use.
It's 20 minutes, but the relevant to this discussion stuff is 17-19 minutes in. But, the whole thing is well done, and sets up the question at hand, IMHO.
It's funky, but your speed varies, as the earth spins each day, from like 1,299,500 MPH to 1,300,500 MPH!