1. What numbers, when written alphabetically (i.e. "one", "two", etc.), have their letters in alphabetical order?
2. The numbers from 1 (one) to 1,000,000 (one million) are written alphabetically, then they are put in alphabetical order. [In this puzzle, consider spaces to come before the letter a. For example, "Nine thousand, four hundred, thirty-six" comes before "Nineteen".]
   1. What number comes first in this list?
   2. What number comes last?
   3. At what position is the number "one" in this list?

Source: Many places.

1. The common answer is "forty". Bill and Ian pointed out that "three" has its letters in the phrase "alphabetical order". After some prodding, Bill also suggested the answers of "e" (the base of natural logarithms) and "c" (the speed of light). I suppose there are other single-letter "numbers" which could be added to this list.
2. 1. First comes "eight".
   2. Last comes "two thousand two hundred two (2202)".
   3. "One" is found at position 449450.

2.3  Looking at the digits, teens, and tens, we see that
     "four", "five", "eight", "nine", "eleven", "fourteen", "fifteen",
     "eighteen", "nineteen", "forty", "fifty", "eighty" and "ninety"
     come before "one."

     Looking at just the single digits, we have 4 possibilities of
     each of N, Nxx (N hundred), Nxxx (N thousand), and Nxxxxx
     (N hundred thousand) (where N is 4, 5, 8, or 9).  Nxx can be
     from N00 to N99, giving 100 numbers, Nxxx can be from N000 to
     N999, giving 1000 numbers, and Nxxxxx can be from N00000 to
     N99999, giving 100000 numbers.  Therefore, the digits give us
     4*(100000+1000+100+1)=404404 numbers.

     Of the teens we have 5 possibilities of each of MN and MNxxx
     (where MN is 11, 14 15, 18, or 19).  MNxxx can be from MN000 to
     MN999, giving 1000 numbers.  Therefore, the teens give us
     5(1000+1)=5005 numbers.

     Of the tens we have 4 possibilities of each of Nx and Nxxxx
     (where N is 4, 5, 8, or 9).  Nx can range from N0 to N9, giving
     10 numbers, and Nxxxx can range from N0000 to N9999, giving 10000
     numbers.  Therefore, the tens giv us 4*(10000+10)=40040 more
     numbers.

     Thus, "one" comes after 404404+5005+40040=449449 other numbers.

     "One" is the 449450th number on the list.