Babysitting ideas for a 4 and 2 year old?

hide and seek

crafts

playdough

freeze dance

inside mini golf (get cups for the holes and ping pong balls for the golf ball)

board games

movies

dress up-if you dont have dresses for them get scarves hats etc...

play vet

you can print out coloring pages for them to color on

you can go to a dressup sort of website like http://www.girlsgogames.com/

Reading stories and then acting them out complete with costumes and sets is always fun. Hansel and Gretel, Rapunzel and Little Red Riding Hood are always favorites.

Tag and hide and seek are fun. As added excitement you can use eyeless, soft stuffed animals and tag with them like dodge ball. Or you can clip ribbons to their clothes and when the person who's "it" gets them off they become it. This keeps it more fair for younger kids.

Baking cookies or cupcakes and decorating them is fun for all ages. Painting or utilizing the craft supplies in the house is also a good idea.

If you have some paper, crayons or paint, and scissors try drawing/painting and collages. Here http://www.toddler-net.com/Games_art_crafts.html you can find specific ideas for art and crafts.

Play dough is also easy and fun.

Try paper airplanes: my boys could play for hours with them.

Do you have some puzzles?

Just get some books and read to them!

Make bubbles.

Play board games.

Take them outside to a playground, if allowed.

Children that age always love stories.

pet carrier.