What do you do daily as a sponge in third grade? For my 7th graders I did daily oral language, but would like other ideas. Our journaling is going to be done at the end of the day as a closing activity, as we will be writing a diary of our year.
Is a "sponge" activity something you begin the day with? How about a five minute frenzy? Those are 100 math facts on a page. I begin the day with a question on the board. They answer it on an index card, then go into SSR. We go over the answers at morning meeting. Often the question is something like DOL. They have to count and find the errors in my message. We go over it at the meeting. We do other kinds of problems too.
I am assuming a sponge activity is a quick game or transition when you have some down time? Here is a game that the kids love when reviewing skills or information. Have them spread out around the room. Choose a student (however you randomly choose-popsicle sticks, etc.) Then ask the student a review question. If they are correct they can move one step in any direction. If they get close enough to another student to touch them, the tagged student has to sit down. Play until one student is left. Hope this is the type of thing you were looking for.