I know that WPF 3.5 SP1 supports a StringFormat in a binding, but can Silverlight do the same? I thought it could, but damned if I can make it work!
StringFormat
Her
I don't know which version of Silverlight introduced it, but you now can. I'm using Silverlight 4 Beta.
http://blog.davemdavis.net/2009/12/silverlight-4-data-binding-string.html
Here's info on Formatting Types, and more for DateTime.
Here's full documentation on Silverlight Binding.