Quote from GateFox
Ooooh, very clever, very clever indeed. String's probably too noticeable though, especially with a texture pack.
Anyway, for the idea... I'd just go with carpets on slabs and stairs, even though I'd probably never use the slabs.
You can use a block update glitch to create it, although it will be messy while you're making it. Get water, put a lilypad on it, replace water with a block. Whatever you place on top of the lily pad wont update.