No new values from Accelerometer

I have a sparkfun accelerometer that I am having a terrible time getting to read properly. I have it wired up with SCL to A5 and SDA to A4, VCC to 5v and ground to ground. With the sketch below I can get a read out but it never changes.
I always get:
0.00
75.00
125.00

Any ideas?

#include <Wire.h>

void setup()
{
  Wire.begin();        
  Serial.begin(9600);  
}

void loop()
{
  Wire.requestFrom(29, 3);    
  while(Wire.available())    
  { 
    float value = Wire.read(); 
    Serial.print(value);        
  }

  delay(100);
}

I have an idea: tell us what type of accelerometer you have and post a link to its data sheet.