How to find missing libraries when compiling apps

[CB]

How do you go about discovering what rpm to install to add a required
library when trying to compile an application?

Current example: I want to try out Tomboy
( http://beatniksoftware.com/tomboy ). ./configure gives me the
following error: 

	No package 'gdk-2.0' found

I've tried doing a 'yum search' and have tried rather randomly
installing a couple of rpm's with the string 'gdk' in them, but that
seems a pretty dumb approach. Is there a better one, or do you just have
to read and comprehend the code to know what to install?