Since Jan. 2006, D. E. Knuth rewards anybody who helps him with a check in the bank of San Serriffe. You can find its coordinates here:
I have an account open in this bank with 0x$1.00 (1 hexadecimal dollar, equivalent to USD2.56). This amount of money comes from a check that D. E. Knuth sent to me in Nov. 2007 because I answered to one of his questions.
Chèque Knuth
I received this check with a copy of the email I sent to him, on which one he had written:
« I enjoyed metting you in Bordeaux. Many thanks! ».
Enveloppe Knuth Lettree Knuth
I've had the pleasure to meet him during the previous month in a conference in his honor and where he received a Doctora Honoris Causa of the university of Bordeaux. During this ceremony I presented my work (in collaboration with J.-P. Duval and T. Lecroq) on the verification of Knuth Morris and Pratt arrays.
Knuth Docteur Honoris Causa Knuth