Hi,
Noobie question:
How is persistent data storage done on an Arduino? (I need to have some data available next time it powers on.) Do I need to have an SD card for this? Or can it be stored on the flash memory directly? (The data is very tiny, less than a kB).
Thanks 
The EEPROM memory already available inside the processor is the simplest solution for you.
A 168 processor has 512 bytes of EEPROM, a 328 chip has 1K, and the Mega 1280 chip has 4K.
Lefty
maybe ...
would be more relevant ;D
I suspect retrolefty meant to post a link here...
These may be useful as well...
http://www.arduino.cc/playground/Code/EEPROMWriteAnything
http://www.arduino.cc/playground/Code/EEPROM-Flash
Yep, pasted without copying, older link posted, face-palmed again 
It's hard being a "God" member at times ;D
Lefty