Is there any way I can download a file onto an SD card from the internet using a wifi or ethernet shield?
If you plan on using the SD card on the Ethernet shield - http://www.arduino.cc/en/Main/ArduinoEthernetShield says it is not supported. It seems silly to go to the trouble of putting parts on a shield and not using them, but then again my Ethernet Shield didn't come with the SD card connector/mount anyway.
However, given both an SD card shield and an Ethernet shield... seems possible.