To begin with, I'll admit that I had to use wikipedia to find the word "heterograph". I knew what I was looking for, but not what the word is. Heterographs are words that sound the same but are spelled differently and mean different things. One of the most common hetergraphs is there/their/they're.
Lately I've been noticing more uncommon heterographs. I can kind of understand the there/their/they're problem...two of those words are not nouns. (Although I also think that with a moment of thought, it is easy to figure out the correct one.) Here are the ones I've seen, with made-up sentences...
"I maid the program last night, so it should be all set." (This one really surprised me and it took me a while to figure out what was going on.)
"I finished the hole thing."
"I took the forth train." (Actually, I think I spelled this wrong earlier, but I've since fixed it.)
Isn't language interesting? What are your favorite heterographs?