Challenging early readers in kindergarten

I'm noticing more children entering kindergarten reading fluently. I am looking for creative ideas on how to challenge these children (alternative activities, modifications, etc.) while others are learning about letter recognition, letter/sound correspondence, etc. For example, during the "message" part of meeting or word study time, our classroom para takes a small group of readers out to the hall to read multiple copies of books I know many other kindergarten teachers must have similar situations. Any great ideas?