I read that you can just put a thin layer on a baking sheet and it'll dry out in a couple days. I tried that but it has been a couple days and its still wet. I'm a little worried the yeast will lose its potency since it will have been out for a few days at least. I was thinking it would be best to take it at its peak and then dry it in a dehydrator at a really low temp. That way the yeast will be at its strongest. Thanks!
Spread it thinner. Check it periodically and you'll be able to see which places are drying faster. Spread the wetter areas out more. Once it's semi-dry you may find you are able to peel it off the baking sheet and flip it over, exposing the wetter underside to the air. Make sure it's in a place where there is at least a bit of air circulation.
The dehydrator could work but it would have to be a very very low temp or you'll kill off too many yeast & LAB. Even if they don't die you'll totally lose the benefit of them being at their strongest, cuz they'll be weak and stressed instead. If your dehydrator has a fan only setting that would probably be a great option.
You might want to mix the starter with water first to thin it out, then spread it thin. I am making some dried starter now, and the first batch was flaking by the next morning - it is about 75F in the house.
http://www.thefreshloaf.com/search/node/how+to+dry+starter
...and it takes days to dry, try dusting the top surface with flour or scraping it back up, feed it and spread it out again. Dehydrators can get too warm. A sheet of parchment works great and let it lay on a rack or towel to encourage drying. A small fan can help blow air over the surface to help drying.
http://www.thefreshloaf.com/node/60059/drying-sd-travel
Maurizio Leo provides methods here.
Be patient when you re-hydrate and revive it. It won't just spring back to prior activity. Can take a few days to grow up.
Tom