If you want an easy-to-use toddler curriculum for ideas, check out www.letteroftheweek.com.
I imagine that you would need to find something you can do with the 2 yr old that you can do in the same room as the older child, so that you're available if he has questions, yes?
Also, crafts and activities for toddlers don't last long. It might be a good time for an afternoon snack, followed by the craft/activity so you can be sure to fill your half hour time slot.
Here are some things we do with our 2 yr old boy:
He loves to watercolor. Now is a great time to stock up on them since school supplies are so cheap.
Also, any sort of simple art project that involves glue-dipping is fun. You can easily make tear-paper art that a 2 yr old can do: cut cardstock into large shapes (triangle, circle, square, etc.) and then tear construction paper into 1- or 2-inch pieces. If you tear or cut the construction paper into strips first, the 2 yr old can help tear the strips into pieces. Once you have a pile of pieces, show him how to dip the pieces into a small bowl of Elmer's glue and stick them to the cardstock shape. Pick a different shape and color every week.
You can also use the glue-dipping technique for lots of other crafts. Toddlers love to dip, dip, dip. Get a paper plate and cotton balls for a sheep. You can either cut out large circles of black construction paper for the eyes, or use googly eyes. You can buy VERY big googly eyes at any crafts store (the bigger they are, the easier for little hands to deal with, and the less of a choking hazard)
We hung a piece of string on our kitchen wall like a clothes line (using 2 cup hooks in the wall) and hang all of this wonderful art work on it with clothes pins. We just clear it off every once in a while to make room for more.
You'll have to prep this in advance, but cut out an animal or person outline using a big piece of manilla construction paper, then cut out features that your son can glue on. it's a good exercise in getting him to think about where noses, ears, eyes, etc. go. When my daughter was 2, she liked to put clothes on stick people. I would draw a big stick person, then use colored or patterned paper to cut out shirts, pants (these were VERY rudimentary, free-hand cuttings!), dresses, hats, etc. and help her glue them on the stick people.
He could put stickers on a blank piece of paper.
Window clings might keep him busy for a while if you have a low window in or near your kitchen.
Use Kleenex Viva paper towels or coffee filters to make "tie dye" art. Use a sharpie to draw something (maybe your shape or letter of the week) on the paper towel or coffee filter, then let the little guy use washable markers to color it in (or scribble all over it!). Let him dip the towel or coffee filter in a shallow bowl of water and watch the colors start to run. Lay it on a kitchen towel to dry before you hang it.
He also likes tracing his hands and feet onto paper. We could trace his hands 100 times and I don't think he'd get tired of it!
Play-doh is a big hit too. It helps to have some of the tools and play-doh toys where you can squish the dough through strainers and make shapes, etc. I agree with another post about saving toys like this specifically for "homework time" so they stay special and continue to hold his attention.
Bake cookies with him. It will be a mess, but he can help stir, and can put balls of dough on a cookie sheet (you hand them to him, and he puts them on the cookie sheet). If your older child is working at the kitchen table, you'll be within earshot if he has a question.
Might be a good time for some sort of electronic toy. They have little toddler "computers" that help kids learn shapes and letters and all that. In fact, if there's a regular computer nearby, check out the Jump Start CD-rom games and activities for toddlers. All they have to be able to do is hit a button or wiggle the mouse to make some sort of action on the screen.
Also, we have "Fun Friday" in my house. (kids get to eat candy, watch movies, wear PJs all day, etc.) Maybe he could get a designated "day off" from homework time and watch a short DVD.
If he can play in the backyard within eyesight, send him out there with 5 or 6 water balloons for a "science project" and have him roll them down a hill or down a slide, throw them in a bucket, etc.
If he's REALLY active, maybe you should invest in a small jumphouse?? We borrowed one from a friend for a while and the kids loved it. They roll up into a big duffle bag, so they're not hard to store. You just unroll it, stake it down and turn on the air. Then the kids jump their little hearts out.
That's all I can think of for now.
Hope this helps!
