You can read through the XML document with an Xml(Text)Reader, that is
forward only pull parsing where your code only pulls in the current node.
The documentation is here
<http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlr
fSystemXmlXmlTextReaderClassTopic.asp>
for .NET 1.x and here
<http://msdn2.microsoft.com/en-us/library/system.xml.xmlreader(VS.80).aspx>
for .NET 2.0.