I've been doing a fair bit of single pitch instructing work recently and found I really needed some rope protectors that were:
1) well designed and actually worked, especially for protecting knots.
2) didn't cost an absolute fortune.
Anyway after a tour of some shops and a bit of experimentation I think I might have cracked it. Please have a look at the two photos below, especially the second one and let me know what you think.
Protection for single strands of rope running over rough rock or sharp edges. 50cm sections of 1/2" B&Q hose pipe with a spiral cut seem effective and secure despite being really easy to fit and remove. See
http://www.climbwest.com/rope_protector_1.jpg
Protection for the central figure-of-eight knots in bottom ropes or other set-ups. A piece of matting fitted with two grommets, two 3mm prussik loops and two 4cm accessory krabs again seems to look like a winner. See
http://www.climbwest.com/rope_protector_2.jpg As far as I'm aware there is nothing like this available for sale.
As well as being after any feedback or suggestions, I had to buy more components (grommets, krabs etc.) than I need for myself so if anyone else fancies a cheap rope protector mat or some length of hosepipe, let me know.