memory stream question

[WebBuilder451]

i have an aspx page with

fu1.SaveAs(@"c:\websites\outlookImportTest\website\Files\uploaded.csv");
Response.Write(fu1.FileContent.Length.ToString());
String[] str =
File.ReadAllLines(@"c:\websites\outlookImportTest\website\Files\uploaded.csv");

i'd like to avoide writting the file to HD if possible. I can move the file
into a byte array , but this is real slow on execution, much slower than
saving the uploaded file then reading it by line.

Is there a way to move the uploaded file into memory then read it by line as
above?

Thanks
KES