This blog post written by Colin Eberhardt describes a technique for associating multiple bindings with a single dependency property within Silverlight applications.
WPF already has this functionality in the form of MultiBindings, the code in this post emulates this function. The simple application below demonstrates this technique, where there are three data-entry text boxes bound to the individual properties of a simple Person object, with the title text block being bound to both the Forename and Surname properties. Try editing the surname or forename fields and watch as the title is updated.