A Linux kernel module that makes a character device that writes ~.
It also makes a /dev/widetilde that prints ～.
Make sure you have kernel headers and shit installed and then just make.
make clean cleans the stuff.
insmod ./devtilde.ko.
dmesg should show a message: ~: Module loaded successfully~!
I've included a udev rule that sets the permissions of /dev/tilde to 0444. You can toss it in /etc/udev/rules.d if you want to.