We are planning a trip in December to go to Maui with our 2yr old and 5mth old. Grandparents are coming, too.

Any suggestions on good locations, condos (2 bedroom, 2 bath with kitchen and washer/dryer) or fun kid and non-kid activities?

I would want to be close to the most activities and not somewhere remote in case the adults get to have a little time while GPs babysit or you want to stroll the children around but be able to get back quickly when everyone gets tired. This means to me the Kaanapali area perhaps within walking distance of that Whaler's shopping area (Whaler's Cove?) Quicker trips into Lahaina will also be possible this way. I would want a nice kiddie pool with nearby shade and pleasant grounds as children often enjoy their resort area more than anyplace we might haul them. If money is not a big object the Kaanapali Alii sure is nice! For less expensive condos in this area... Come on Fodors posters, share your experiences!

It never ceases to amaze me that there are parents out there hardy enough to fly all the way to someplace like Hawaii and have a 2 yr old and an infant with them! Wow!

You might investigate the Kihei/Wailea area. Numerous condominiums at various price/amenity levels. Try for instance drhmaui.com. Smaller, protected, gorgeous beaches. Kihei has the vibe of a beach town where real people stay and live. Wailea features low-rise, lower density, high cotton living with great dining and top tier shopping. Driest weather on the island. Still, many prefer Ka'anapali, a community of higher density, high-rise hotels and condos on a long beach that vanishes at times. Proximity to Lahaina with its street life could be attractive. In winter there are often strong swells in west Maui that hinder swimming in the ocean.
Note that the second half of December is extremely busy. Often two week minimum stays are required and few deals on accommodations or cars are offered.

The Whaler Condo in Kaanapali is nice not fancy , good pool , close to everything in whalers village. The whalers village area has open air shoping and there are many grills and restraunts in the area. There is a board walk that fronts all the hotels and black rock is near by to snorkel.

I second the Alli and the Whaler.. have stayed at both. The Alli will be more expensive but great pool area for the kids. The location at Kaanapali Beach for the Alii or the Whaler is great.. You can walk on sidewalk all along the beach from one end to the other. It would be great for walks with your stroller without having to pack everything up and go in your car. The Alli does have washer and dryers in Condos. The Whaler does not. It has coin operated shared washer and dryers on each floor which my get alittle spendy with two babies. They may have a few units with washers and dryers. Would be worth a phone call to the Whaler to find out. The Whaler is less expensive and not as fancy as the Alii. Good Luck.