I agreed to make a cake for 150 for a first birthday. Now I have no ideas. The little boy likes monkeys so I want to incorporate that. Does anyone have suggestions for making the cake feed 150 and not 3 tier, and for getting monkeys and stuff on this cake? thanks!! oh yeah, I don't want the cake covered in fondant either. I know it looks lovely, but the taste/texture gross me out!!

Since it is a first birthday I assume that there will be kids there...Perhaps find out how many children will be there among the 150 (are they nuts for having a 1st birthday that big!?), and make cupcakes for the children to coordinate with the cake. That should cut down on the size cake you need to make for adults and also make it easier to quickly serve the children cake.

I did a monkey cake for my son's 2nd birthday and for the kids I made banana cupcakes frosted with chocolate with a banana piped on them. If there are a ton you could do some banana cupcakes with chocolate with banana (yellow bc) and some with cream cheese frosting with monkeys piped on.

You can see the cake/cupcakes that I made http://www.cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1546696.

I've done a couple of monkey cakes that got rave reviews, despite their simplicity. One was a round cake decorated with diff color polka dots and the topper was a monkey sitting between 2 palm trees. You can do 16" round, 3 layers if you need that many servings. The other was a sheet cake, 2 layer, that serves about 100 with the Wilton monkey pan on top.
You can add a party hat to the monkey with an ice cream cone, too.
Just a couple of suggestions.

I did a buttercream cake last year for my nephew with Fondant Monkeys on it. They were fun to do.

Have you looked through the monkey themed cakes in the photos?