Here's some advice I found in the comments over at Tamera's on the topic of writing letters to elected officials. This comes from someone whose job was to read the congressman's mail so he knows whereof he speaks. Some of the things you've heard are flatly wrong, so give this a quick gander, and then put together some quick, concise, ORIGINAL, content for your elected overlord.
No, he probably won't actually read it, but his office does keep score. Get out there and run up the score. BTW: E-mail is actually more effective than snail mail.