Here are some sounds that you can use for your computer sounds (such as AOL Welcome, Goodbye, etc.).

Aragorn: "Mae govannen, Haldir."
Aragorn: "Mae govannen."
Aragorn: "You are most welcome."
Gandalf: "Do not look for welcome here."
Wormtongue: "He's not welcome."
Theoden: "Why should I welcome you, Gandalf Stormcrow?"
Haldir: "Mae govannen, Legolas Thranduilion."
Haldir: "Mae govannen."
Elrond: "Welcome to Rivendell."
Bilbo: "Welcome, welcome."
Galadriel: "Welcome Frodo of the Shire."
Merry: "Hello Frodo!"
Bilbo: "Hello Frodo my lad!" Theoden: "Why should I welcome you?"
"Hello this is Orlando Bloom." "Hello this is Elijah Wood."
"Hello this is Viggo Mortensen." "Hello this is Sean Astin."
"Hello this is Dominic Monaghan." "Hello this is Billy Boyd."
"I'm Christopher Lee. Welcome." "Hello this is Brad Dourif."
"G'day this is Karl Urban." "Hello this is Bernard Hill."
"Hi this is Andy Serkis." "Hello this is Ian Holm."
"Hello this is Liv Tyler." "Hi this is Miranda Otto."
"Hello this is Peter Jackson."
Eomer: "Farewell."
Galadriel: "Namarie."
Elrond: "I Aear can ven Namar."
Galadriel: "Farewell, Frodo Baggins."
Bilbo: "Goodbye Gandalf."
Gandalf: "Goodbye, dear Bilbo."

Some of these sounds are very low or not clear, sorry about that! "Hello, this is..." cast clips from the official Lord of the Rings site.