my friend made up the word bromance for when two hetero dudes are overly affectionate.

the only real saying of mine that has kind of caught on is - whenever you are curious or interested in something, you just slip a "bi" in there. example:

a - "I went hang gliding this weekend"
b - "I've always been bi-curious about hang gliding"

I've made words up, but my biggest accomplishment was inspiring someone else to make a word up: she called me "accostic" (as in adjective form of the verb, 'to accost', possibly confused with the word 'caustic').