We got Madison an inexpensive video camera off amazon.com for Christmas (like $20). It takes still shots as well and she loves it. It works best outdoors where it is brighter. I think that's a great idea for Eli!
I mentioned all these ideas to everyone that came to Faith's birthday party today (really it was just grandparents, and grandparent type people) and the LOVED them. Now I'll have to see if I can find one at my local stores.
Playing with ice reminded me that as a kid my Mom would give me a bucket of water and a paintbrush to draw on the sidewalk...and I loved it! I also enjoyed making hand and foot prints and watching them disappear.