How should I implement ExecuteAsync with RestSharp on Windows Phone 7?

Old question but if you are using C# 5 you can have a generic execute class by creating a TaskCompleteSource that resturns a Task of T. Your code could look like this:

public Task<T> ExecuteAsync<T>(RestRequest request) where T : new()
    {
        var client = new RestClient();
        var taskCompletionSource = new TaskCompletionSource<T>();
        client.BaseUrl = BaseUrl;
        client.Authenticator = new HttpBasicAuthenticator(_accountSid, _secretKey);
        request.AddParameter("AccountSid", _accountSid, ParameterType.UrlSegment);
        client.ExecuteAsync<T>(request, (response) => taskCompletionSource.SetResult(response.Data));
        return taskCompletionSource.Task;
    }

And use it like this:

private async Task DoWork()
    {
        var api = new HarooApi("MyAcoountId", "MySecret");
        var request = new RestRequest();
        var myClass = await api.ExecuteAsync<MyClass>(request);

        // Do something with myClass
    }