Tap codes has a pretty cool history, you can read more about it in the wikipedia entry for tap codes. A minor issue is that the C and K in the 5x5 tap codes are mushed together. What if we extend the table to 6x6. And what if we arrange it in different ways. Here is just some experimentations to that reguards.

Feel free to use it. Please do let me know how you find it. It's not ment to be a serious form of communication. But it is easy to explain (not sure if any easier to master compared to morse code).

Letter Freqency

12,000	E				| 2,500	F
9,000	T				| 2,000	W, Y
8,000	A, I, N, O, S	| 1,700	G, P
6,400	H				| 1,600	B
6,200	R				| 1,200	V
4,400	D				| 800	K
4,000	L				| 500	Q
3,400	U				| 400	J, X
3,000	C, M			| 200	Z

SOURCE: What is the freqency of the letters of the alphabet in english

Tap the number of rows, then tap the number of columns

	
	 Non Standard 6x6 Tap Code ( Arranged by frequency of letters )
	
	   | 1 | 2 | 3 | 4 | 5 | 6 |
	---|---|---|---|---|---|---|
	 1 | E | A | O | D | F | Z |
	 2 | T | N | R | M | B | X | 
	 3 | I | H | C | P | J | 3 |
	 4 | S | U | G | Q | 2 | 6 | 
	 5 | L | Y | K | 1 | 5 | 8 |
	 6 | W | V | 0 | 4 | 7 | 9 |




	 Non Standard 6x6 Tap Code ( Arranged by Alphanumerical Order )

	   | 1 | 2 | 3 | 4 | 5 | 6 |
	---|---|---|---|---|---|---|
	 1 | A | B | C | D | E | F |  
	 2 | G | H | I | J | K | L |
	 3 | M | N | O | P | Q | R |
	 4 | S | T | U | V | W | X |
	 5 | Y | Z | 0 | 1 | 2 | 3 | 
	 6 | 4 | 5 | 6 | 7 | 8 | 9 |
	



	 Non Standard 6x6 Tap Code EXTENDED PROSIGNS ( Arranged by Alphanumerical Order )

	   | 1 | 2 | 3 | 4 | 5 | 6 |
	---|---|---|---|---|---|---|
	 1 | A | B | C | D | E | F |  
	 2 | G | H | I | J | K | L |
	 3 | M | N | O | P | Q | R |
	 4 | S | T | U | V | W | X |
	 5 | Y | Z | 0 | 1 | 2 | 3 | 
	 6 | 4 | 5 | 6 | 7 | 8 | 9 |
	 7 |EOW|ERR|ITT|SS |UND|WAT|
	 
	 EOW : END OF WORK
	 ERR : ERROR
	 ITT : Invitation To Transmit
	 SS  : Starting signal
	 UND : Understood
	 WAT : Wait



	 Non Standard 6x6 Tap Code EXTENDED PUNCTUATIONS ( Arranged by Alphanumerical Order )

	   | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
	---|---|---|---|---|---|---|---|---|---|
	 1 | A | B | C | D | E | F | . | ( | + |
	 2 | G | H | I | J | K | L | , | ) | - |
	 3 | M | N | O | P | Q | R | ? | & | _ |
	 4 | S | T | U | V | W | X | ' | : | " |
	 5 | Y | Z | 0 | 1 | 2 | 3 | ! | ; | $ |
	 6 | 4 | 5 | 6 | 7 | 8 | 9 | / | = | @ |
	



	 Non Standard 6x6 Tap Code EXTENDED PUNCTUATIONS & PROSIGNS
	 ( Arranged by Alphanumerical Order )

	   | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
	---|---|---|---|---|---|---|---|---|---|
	 1 | A | B | C | D | E | F | . | ( | + |
	 2 | G | H | I | J | K | L | , | ) | - |
	 3 | M | N | O | P | Q | R | ? | & | _ |
	 4 | S | T | U | V | W | X | ' | : | " |
	 5 | Y | Z | 0 | 1 | 2 | 3 | ! | ; | $ |
	 6 | 4 | 5 | 6 | 7 | 8 | 9 | / | = | @ |
	 7 |EOW|ERR|ITT|SS |UND|WAT|
	 
	 EOW : END OF WORK
	 ERR : ERROR
	 ITT : Invitation To Transmit
	 SS  : Starting signal
	 UND : Understood
	 WAT : Wait

In general however, from what I read online, it's still easier to learn morse code. (But this is easier to explain to newbies, with a reference sheet).