Plastic 'Sliders'

How about something like this :

This item is made for books and also made to not mark up your pages. So maybe it would work for your game and reduce damage to whatever you are using them on.

see more images and what it is at :
http://www.levenger.com/Pagetemplates/Product/MorePhotos.asp

As for plastic related items like this how about :

from an Amazon site

which is just a plastic paper clip. and as Darke mentioned might damage your cards over time. I think you might be able to find a plastic version of the first item I listed above, but I dont have time to search for it.

Oh... I thought about one issue with the first item, they look pretty dangerous !! So no matter who your target audience might be, it might be bad to use those exact items in a game. You know, to avoid getting sued because of the morons in the world! If it is just for your own prototyping pleasure, dont blame me if you poke your finger!! lol

One other idea, if you could manage to create a *slide ruler* type item to go around the card. It might work well. If you look at images on google of *slide ruler* you might see what I mean. But it does not allow for two sided selection, which seems to be what you need.

Another idea, though I have no clue what they it would be called, night be a device that looked something like the slider in this eraser image below:

If you could make a simple board component that would *wrap* your character card with two of these type of sliders one on each side (assuming the card is like the ones in Arkham Horror style) you could put any card in the middle and slide your sliders so they point at the current state.

Not sure if I am making any sense, but basically think of any type of slider, on each side of your card. But the sliders are in a seperate component which has room to place your desired character card into the middle. So you slide in your character card and move the sliders into the correct postion to point at the current state/stage of the card.