We're having my son's baptism and daughter's 3rd birthday party together on the same day. My Husband says just one cake..boo..but makes sense. Anyone have any thoughts on how to decorate for something like this. My daughter sees any picture of cake and declares that's the one she wants so she's really not picky Althought her very favorite color is pink but that doesn't really work for a boy. They boy baptism part of the cake wouldn't have to be religious..just looking for a cute way to combine
Thanks!

What about something like this? You could make the pink side completely birthday.

http://cakecentral.com/gallery/2323689/hishers-communion

For similar occasions, when you don't need a lot of cake, I have placed single layers of cake side-by-side and decorated each as needed. Here are a few samples:
http://cakecentral.com/gallery/2221228/circus-lion-cage
http://cakecentral.com/gallery/1369704/double-hearts
http://cakecentral.com/gallery/1349755/dueo-occasion-theme
http://cakecentral.com/gallery/1197295/birthday-and-anniversary

Another possible idea would be to devide a sheet cake somewhat similar to this:
http://cakecentral.com/gallery/1329834/pansies-for-mom
the center banner can say their names w/each 1/2 decorated to their likes.
OR one last idea: an open book cake w/each page for each occasion:
http://cakecentral.com/gallery/27075/open-bible-for-church-anniversary

Thanks for the links! Definitely gave me some ideas to think about

I say make 2 smaller cakes. Each child deserves a separate cake for such events.