Hi guys,
I needed a thing to graph data sent from arduino for my UAV thing, so I put together a program in C# using the excellent ZedGraph graphing libraries.
It allows you to graph upto 10 different channels on one graph (limited only because I couldn't come up with more line colours), and you can change how many samples you want to store in the graph. You can zoom in to the graph, save a picture n'stuff.

It is not super fast, i.e. not meant to be an oscilloscope, but 100Hz is not a problem.
Here's a link to the download: https://sites.google.com/site/iluvtocnc/DataPlot3.zip
Here's a test sketch:
void setup() {
// initialize the serial communication:
Serial.begin(9600);
}
void loop() {
Serial.print(analogRead(A0));
Serial.print(',');
Serial.print(analogRead(A1));
Serial.print(',');
Serial.print(analogRead(A2));
Serial.print(',');
Serial.print(analogRead(A3));
Serial.print(',');
Serial.print(analogRead(A4));
Serial.print(',');
Serial.println(analogRead(A5));
delay(10);
}
I apologize in advance for any crashes from bugs, the user inputs have zero error checking, since this was a Sunday afternoon job. This is a .net program, so you may need to have .net framework to get it working. I have only tested this on Win 7.
-Z-
I have a lot of people ask me for the code, it's here!!!! ############################
I have posted in the source code here: http://arduino.cc/forum/index.php/topic,80466.0.html