Sometimes a string isn't enough, you need a stream. Unfortunately, there isn't a direct method to stick a string into a stream. But we are saved! MemoryStream will take bytes... here's how to convert your string into a series of bytes so you can get that all important StringStream. No, I'm not going to make a StringStream class though you certainly can fulfill your masochistic class explosion desires.
String request = "I can has cheezburger?";
MemoryStream stream = new MemoryStream(Encoding.Unicode.GetBytes(request));