Currently one of the angles that we're looking at on Kryptos, is palindromes. This is because of an unusually large number of doubled letters both in the ciphertext and involved in deliberate misspellings of other words (underground : undergruund, illusion : iqlusion), and because there are some other related pieces by Sanborn that involve Morse code palindromes (such as a line with some leading dots and the word "invisible").

e e e e e e invisible:
. . . . . . .. -. ...- .. ... .. -... .-.. .

reverse the line: . ..-. ...- .. ... .. -... .- .. . . . . . .

Keep the spacing the same, and it's close but not intelligible: "efvisibai e e e e e e ". But change the spacing, and it comes back to the word "e invisible e e e e e":

. .. -. ...- .. ... .. -... .-.. . . . . . .