I usually don't make blanket proclaimations, but Every Church Needs A Play Altar. Really. We added one to our preschool classroom a couple of years ago, and it is a favorite activity week in and week out.
Ours is a side table that was just sitting around. A sewer in the congregation made simple altar cloths in the liturgical colors with matching stoles (actually, they're reversable, one color on each side, 2 sets):
We added an inexpensive brass communion set and a couple copies of Gretchen Prichard's Alleluia, Amen. Occasionally, we'll have some wafers. But the kids go *crazy* when they have wafers and would go through a roll a week if we let them. So it's a special occasion thing.
I grew up with a Children's Altar, but it was as Revered and Transcendent as the main altar. Just like kids like to have a play kitchen or a play workshop, they also like a play altar. If you need any help figuring out how to make it work at your church, just ask!