In our company, we are using a custom version of the Parameterized Trigger plug-in that includes a Groovy script condition additionally to the result condition. It allows to create more complex trigger conditions, based on the build or on external criteria. For example, we use this script, among other things, to trigger another project build at night only (see attached screenshot).
Adding this feature is very easy and I think it could be nice to add it to the main branch of development.
I provide also a diff that illustrates how we added this new feature to the 2.4 code. Please note that this adds an additional dependency on JDK1.6 for the scripting support. And on Groovy of course.