Speed vs. size

I declare local variables and function return types as int, even if they hold just a boolean value.
It's something to do with asm statements generating extraneous bit masking to make sure values are in an 8-bit range if they are chars I guess.
In fact, this shouldn't do anything to affect program size/memory usage because the stack is word-aligned, isn't it?
What do you do? Your dynamically-typed languages are useless here. Discuss.

>>2
You do realize that you could pack as many as 5! three-valued variables into a single char, right?