I need a simple JSON-RPC 1.0 client in C#, preferably using .NET 2.0 or later. I checked out JRock 0.9 They have several samples including Yahoo reader, but the samples demo JSO
Here is an example of a .net4 client exposed through Observables (Rx). http://jsonrpc2.codeplex.com/SourceControl/changeset/view/13061#63133
Here is an almost identical wp7 client that is also exposed through Rx. http://jsonrpc2.codeplex.com/SourceControl/changeset/view/13061#282775
Both of those examples do their work asynchronously so they may be more complicated then you are looking for, unless of course you wanted examples that were asynchronous. :)
Good Luck!