I've lost a few things to them too I believe, and have an excessive number of them in my yard and garden beds. My solution so far, is to slide a toothpick or wooden skewer down along the stem, depending on the size of the stem. I had read to do this to prevent cutworm damage, but it seems to help with the rollie pollies too. I also remove any group of them I find near the base of plants (and squish them). I'm wondering if there is anything else that can be done(organically) to discourage their presence.

They're actually crustaceans, and are fairly closely related to shrimp and breathe through gills so they need moist conditions to live.

They usually prefer decaying material to living plants, so maybe it would help if you left a spot around the plants without the mulch. That might leave that area a little drier and the mulch might attract them away from the plant.