My Janome dealer gave me a free yardstick when I bought my 6600. It's the "bendy" kind, though - probably made from sawdust and glue and mostly held together by the bright yellow paint that covers it!
I have a metal yardstick and a metal meter stick that I bought online, I think they were both pretty inexpensive. My niece and nephew thought they were great for "playing swords" though, so they're kind of beat up on the edges now. *sigh* LOL