Some silly entries there, but this is spot on:

The Two Things about Linguistics:
1. You already know more about the grammar of your native language than could ever be taught in a class. (synchronic linguistics)
2. Language change is inevitable, and neither bad nor good. (diachronic linguistics)
-Neal Whitman

“Reading menus” gets a new meaning for videogame players. When I started learning Japanese I was astonished at how much Japanese in RPGs is really just English.

If I might be so bold, my suggestion of Two Things about Kanji goes contrary to the current trends on RTK-style mnemonics:

1) The phonetic nature of phonetic components matter.
2) Don’t underestimate the value of neuromuscular exercise.

Philosophy:

1. Knowing what all the terms mean takes you 90% of the way there.

2. Everyone tries to kill Plato, but no one succeeds.

The Two Things about Religious Studies:

1. The term "religion" has proved undefinable.

2. If you are concerned about the implications of the previous thing you are thinking harder than 80% of the people in this field.

I disagree with #1, if you're talking about restaurant menus. Katakana is found on menus like at Macdonalds. Nihonryouri is mostly in kanji. On my first trip to Japan, I puzzled over kanji I had never learned in classes, like bento, sashimi, etc.
And for that matter, most of the Japanese software menus I have encountered used kanji, like 印刷 instead of プリント. Maybe the katakana menus is on games, I wouldn't know, I don't play Japanese games.

Charles, what you're missing is that to a kid from South Carolina on his first trip to Japan, the menu would not be appreciably more comprehensible if it said, "THIS IS SASHIMI, Y'ALL." "Sa-hwhuh?"

The other advantage of katakana first is if you misread hiragana you are unlikely to realize you have misread it, since you probably don't know much Japanese yet. (The exception to this would be illiterate Nisei.) If you misread katakana, it won't turn into an English word, so you'll know you're doing it wrong.

Of course you can master both in approximately two months, so it's not a super important question which comes first.

Avery: But what IS the difference between religion, magic, and science?

"Sufficiently advanced technology"?

Wafers?

Carl: It's true, katakana won't get you far in an all-Japanese restaurant, but they're still more useful than hiragana in that context, and telling people to learn kanji first would just be perverse. Historically faithful, but perverse.

Matt,

I think we agree.

I think you're cheating by having a 'plus' in your second Thing.

When I first started out, most of my reading practice was from ads on the subway. The nice thing about katakana is that it's used to write whole words. Very few words that a beginner might know are written in pure hiragana.

Whoops, sorry, Carl (and Charles). I meant Charles.

Tom: I was hoping no-one would call me on that.

katakana is used for a variety of foreign words or gairaigo not just english so as a note to Carl you might still not realise its correct/incorrect even when you are reading it right.. e.g Gelende anyone...