Help! Inside Activity Ideas for 3Yo B-day Party!

Get a big sheet of kraft paper and draw a big, giant car on it (or a couple cars, or a racetrack with several cars, etc--it doesn't have to be professional, just recognizable for 3yos, LOL) and put it down on the floor (linoleum or tile or hardwood) and put down a box of markets and crayons and stickers. Get some glue sticks and some stuff to glue (cotton balls, whatever). If you're worried about them making a mess, put down an old shower curtain or painter's drop cloth underneath the paper.

Do a "Fix the Tire on the Car" along the lines of the Pin The Tail on the Donkey. Cut out some construction paper circles, and draw another big car on another sheet of paper and tape it to the wall.

You could do a "Find the Lost Race Car" (Hey they are 3, right, so they aren't going to question if it makes sense). Take some of those plastic Easter Eggs and put a Matchbox car, one in each, and hide them around the house/party area. Do one for each child, and maybe a couple of extra (write names on them, so that each kid is guaranteed 1). The dollar store has decent cars sometimes.

you could do simon says, freeze dance, musical chairs can make them all car themed....simon says....drive like a car, honk your horn. for freeze dance they can be cars and when the music stops they stop, of couse you will be playing the them song from cars. I have done musical chairs where the one who doesn't get a chair gets to stop and start the music so they get to have fun even though they lost. As for games prizes, you can make a game car and stamp it after they complete the game and then just give a goody bag at the end.

I had the same problem for my son's 4 year old birthday party last month. had a picnic scheduled at the park and the weather report said it was going to rain. I ended up scheduling a last minute party at the Lagrange, Illinois, Park District. They have a huge indoor playground with padded floor so the kids can run around and not get hurt. It costs $38/hour for a private party room and we rented a room for 2 hours. I paid an additional $20 to allow our party goers to have access to that indoor playground. Our party cost less that $100 with a $50 refundable deposit I got that back within a week. I just moved all of the food that we were going to have at the park to the private room we rented. All the kids had a blast and you don't have to worry about activities for the kids as they all ran around the entire time on the playground. Here is the link for the Lagrange Park District: http://www.pdlg.org/rentals/rooms.asp.
They do have the option of renting a bouncy for the kids if you still wanted to do that. Lagrange is only about a 1/2 hour drive from Chicago so it's not a bad drive. Most of our friends made the drive from the city and had a good time!

we did a carnival type party and used the baby pool, but u could use a bucket and got the magnetic fishing rod game from the dollar store...then u can set up water bottles and have them knock them over with a ball, and then if someones crafty they could do a quick cheap wood cut out of something and then u could throw a ball through it...i went to the dollar store for prizes and then they had note books on sale for 10 cents and crayons for 10 cents at cvs so i got a bunch of those and then glow sticks and the kids loved them and bubbles

how about pin the tail on the donkey or face painting. For my daughters party I bought foam picture frames and foam stickers from the dollar store so not expensive and a craft they can do on there own since its just stickers!