[MichaelGG]

We were using .NET's WCF messaging system, but wanted a faster/smaller format. http://code.google.com/p/protobuf-net/ let us keep our code the same, while using protobuf for the wire format. Worked quite well.

Another approach to consider is using a text format (XML, JSON), then running it through fast compression like QuickLZ. This has the benefit of not having to change the program much more than a call to compress/decompress.