I recently participated in a "busy bag" exchange. The idea is that you make an activity that can fit in a bag and then pull out the bag to keep your active toddler busy while you need some peace and quiet. Exchanges allow you to make a single bag multiple times, and then you end up with as many different activities as participants.
I'm looking forward to pulling out our loot when Matthew is a wee bit older. Elizabeth was very keen to play with all his new activities, but he doesn't quite have the fine motor skills for some of them - eg Matthew's version of a busy bag where the kids squeeze a clothespin and clip it to the side of a box is to dismantle all the clothespins into numerous pieces.
I made a geoboard as my contribution. It was so popular that I actually ended up making a couple of extra ones - one for Elizabeth and the other went to Isabelle's and Xander's house. You can use them for all kinds of math activities so they are trendy in the homeschooling community, but my kids mostly just like to make drawings.