i have a couple...
A) MORSE CODES
look up the morse code on an internet site
for example http://www.babbage.demon.co.uk/morseabc.html
now try playing single letters or whole words sticking to the morse code alphabet...lets say the dots should signify an F and the bars signify an E --- so playing the word "cool" would be
[ _ . _ . _ _ _ _ _ _ _ . _ . ]
[ 0 1 0 1 0 0 0 0 0 0 0 1 0 1 ]
as you can see , played with 16th notes this would be a 7/8 rhythm :)
now you could also say ... the dots are 16th notes, and the bars are 8th notes ... now the same word "cool" would look like this (played on the open E string)
[O 00 00 0 0 0 0 0 0 00 0]
the possibilities are endless ! the good thing is, you will play stuff you wouldn normally play
B) BRAILLE ALPHABET
look up the braille alphabet
for example http://www.nbp.org/alph.html
now lets say you play a muted string for every small dot and an open string for every large dot
then the same word "cool" would go like this
[ OOxxxx OxxOOx OxOxOx ]
of course you can also make up your own style, lets say whenever theres an O you play the open string, and for every X you play a note outta any scale... you know...
because of the nature of the braille alphabet you have 6 steps per letter, but you can easily omit the bottom row, so you only have 4 steps ...
the good thing is ... you can download braille and morse fonts for windows...do so, type in any text you want, change the font and print out really wicked exercises :)))