I built a Pulsecounter & Datalogger using the new Arduino Ethernet and Arduino22 environment.
It includes SD card logging, webserving, NTP clock synchronization over the ethernet.
You can find a description along with the code (GPLed) at http://marco.guardigli.it/2011/11/tomware-arduino-ethernet-datalogger.html
I will have to evolve it including FFT capability of high frequency multi channel analog samples. Will keep it posted.