If you fly anything with more of a slow flyer type prop installed, most likely you are running a prop saver rubber strap to hold the prop onto the shaft. Prop savers are nice in that they do just that - they save your prop. Especially when you come in for a belly landing and the prop is still spinning either from the wind or from accidentally still having power applied, it is likely that you will snap a prop when it hits the ground spinning on landing. The prop savers allow the prop to "break away" from the shaft gently without snapping or at least making this much less likely. Well, the frustration I have had with them, is that they dry rot and fatigue pretty quickly.
Many online RC shops charge quite a bit for prop savers so many turn to videos and how to's on the Internet of other things you can use for prop savers such as rubber bands or wire ties, however, these just aren't quite as nice and easy as just using prop savers. Of course from Hobby King you can buy them in bulk very cheap. The frustration with that is that when I have checked, they have been hard to find in stock in the US stores and ordering from the International stores can take quite a bit of time in shipping. I wanted to let you guys know of a cheap replacement that I found at my local Home Depot store in the plumbing section.
The replacement for prop savers are actually just o-rings that you can find in the plumbing section. They usually have an assortment of sizes, but the closest size I found for the prop savers I was using was a #12 O-Ring from Danco. These were extremely cheap, rivaling the price at HobbyKing, but actually cheaper, because of no shipping and not having to wait! These were roughly $2.75 from Home Depot for a package of 10 o-rings. I am sure that other home hardware stores such as Lowes will have the exact ones if not something similar.
Take a look at the pics below and comment below of any other things you guys are using for prop savers or if you have found something like the below you are using.