Who told you that it is "safest"? I have taken thousands of digital photos, and have only formatted the SD cards once or twice.
Original poster - I agree with the recommendation to get a card reader. They cost less than $20. I have never used the transfer software that is included with cameras. You have the most control with a card reader and Vista/XP/WIn98 explorer.
Good luck!
Originally posted by lapeen I was always told that reformatting the card is the best/safest way to delete files off the card... so that is how I have always cleared my cards after uploading the pics onto the computer.