The number 1-866-868-4433, a toll free call in the US, is the Hail to the Thief Hotline. The At Ease Forums has information on navigating the options callers are presented:
1) Rotary phone – when chosen, you’ll hear a loud long tone until you press a number, at which point you can press # to return to the menu.
2) Any option chosen here will let you hear “I Will”. Press * during “I Will” to hear “2+2=5”
3) Any option here will let you listen to “Go To Sleep”. Press * during “Go to Sleep” to hear “2+2=5”
4) This will read a list of websites Radiohead endorses(like at Radiohead.com), if you press a number while she is reading them she’ll ask to you “Please let me finish!”
5) This will just have the lady saying “Cobweb” over and over and over…
6) This will ask you for a 10-digit social security number. Whatever you put in will just lead to her saying “Hail to the Thief” and sending you back to the menu. How clever.
7) This will let you listen to “Sit Down, Stand Up”. Press * during the song to hear “2+2=5”
8) She will say “I told you not to press 8.” and hang up.
9) This will re-read the menu options