We had a junkyard of old ice hockey skate guards, including some ones currently in use like the RollerGuards which turn you hockey skates into Rollerblades/Rollerskates. Also Ireview the boot-like "Skaboots" and other cloth and traditional skate blade guards.
Things to consider:
* durability
* dry and not rust the blades
* bottom surface and how they perform on slippery surfaces
* ease of attachment
* cost, inexpensive, expensive