I have for sale a Really Right Stuff L-plate for the Canon 450d/Rebel XSi, in like-new condition. US $100 (by Paypal only, please) includes shipping in the continental U.S. I'll also ship to Canada - PM me with your address for shipping charges. I'll also consider a trade for the same item for a 350d (Rebel XT) or trade & cash for a standard (i.e. non-"L") RRS plate for the 350D. PM if interested.
Greg
Plate has been sold 3/22/09.