Aqua sand. It makes a bit of a mess, but I pull it out when we're stuck inside, and it keeps the kids busy for awhile.
Newspaper basketball. Use wadded up newspaper and tape to make a ball. Pull out some laundry baskets for baskets. Move the furniture around to make enough space for a game. The ball is soft enough that it won't do damage in the house.
We also do blanket forts on rainy days - those work great. If you can get a large appliance box, those are great, too. You can help the kids make it into a fort or whatever they want to use it as.
Books on CD. These save me on days I need to work from home.
You said no arts and crafts, but have you tried folding paper airplanes? The 2 year old would be too small to make his own, but the 5 year old wouldn't, and a lot of little boys who don't like crafts will sit and fold paper airplanes, especially if you teach them a couple different styles (there are lots of great kits cheap in the bookshops). The two year old would be big enough to throw them.