What are some unorthodox, cornball, or completely off-the-wall ways people might send a message to someone? ~

Put a bottle with a message inside in their swimming pool or no swimming pool just leave it on the ground outside their door during the dark hours.

Put the message in a fish.  I know you will know where this idea came from.

Using a language you don't speak, write a song about an octopus's pet gerbil's secret love hamster, making sure that each note of the song is written to spell out a the botanical name of any flower or tree when read sideways while looking in a mirror.  
Record yourself singing the song backwards into takettle, then post it on Youtube.  They WILL get the message.

Send it in Klingon.