This is a list of two-letter words in English (compiled by the Scrabble people). Since they're trying to list only one (brief) definition for each word, some of their definitions are very funny: "do" isn't the present nominative form of "does" or "did" but "a note on the scale"; there's also "on: batsman's side of wicket" and "or: the heraldic color gold." On the other hand, "be: to have actuality" is quite philosophical, if probably only unintentionally.
I don't like Scrabble, or crossword puzzles either, at least very much, but I do love words, and I think I love very short words best. I think it's because they're really the closest to us, so close that we don't really understand what they mean. (See Heidegger, Wittgenstein.)
Here's a quiz (if you like, you can post in the comments): Pick your five favorite two-letter words.
Here are mine:
it(Remember, I used to be a logician.)
If you're not into the whole connective thing, there are some great deictic tools -- "at," "on," "in," "by," "of" -- or pronouns: "me," "we," "he," "us." Or whatever floats your boat.