For anyone like myself who has limited access to professional sewing supplies, check out www.wawak.com (http://www.wawak.com).
They also have excellent sales! They'll often run a special for "Threads" magazine readers that's just crazy: $20 off a $40 order. Last summer I ordered one thing I needed (can't even remember what), and ended up getting "free" a French curve ruler, a pin-hem marker, and a scalpel seam ripper!