OData from Silverlight without Repository Pattern

I am trying to create a sample app using OData and Silverlight, using (what else?) the Netflix service. I've already succeeded in creating the app using WPF, but am struggling to port my service class to an async model.

My existing service class (simplified) looks like this:

public IEnumerable<Title> BlockingSearch(TitleSearchParam param)
{
    var catalog = new NetflixCatalog(new Uri("http://odata.netflix.com/Catalog/"));

    return catalog.Titles.Where(t =>
                            t.Instant.AvailableFrom > param.InstantStartDate && t.Instant.AvailableFrom < param.InstantEndDate &&
                            (string.IsNullOrEmpty(param.TitleName) || t.Name.Contains(param.TitleName))).ToList();

    }

All of the examples of consuming OData asynchronously employ some kind of Respository Pattern and/or require an instantiated collection to be passed in. I would like to model the method signature for the Silverlight/Async call to look something like this (with the service class itself being stateless):

public void AsyncSearch(TitleSearchParam param, Action<IEnumerable<Title>> completedCallback, Action<MyErrorClass> errorCallback, object ca开发者_如何学编程llBackOwner)
{

}

I think I could so something along the lines of what MS outlines in Calling Synchronous Methods Asynchronously, but I was hoping there was a more elegant solution that I was missing.

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As you already know, you can always run the call on a different thread than the UI thread, so there will be no blocking per se. That seems like a decent enough solution. Then you can (in fact, must) use dispatchers to handle results coming from callbacks if you intend to use them with UI.