The way that card is placed in there though, I'm not sure how often I really would want to take the SD card out. My thinking is more along the lines of buying a big enough card and leaving it in there. The actual 'slot' that pops up feels way too fragile for my liking. Especially for 'in the field' swaps. For the price of SD cards these days, I'd just buy another one for the MP3.
Although I'll admit -- when I run out of space on the digital camera card, I can always harvest the SD from the eXplorist for 'one more' shot. As long as the camera is a standard FAT filesystem on it.
On another note, I haven't figured out a way to format SD cards in the actual unit, so when I tossed the card from my MP3 player into the 600, it froze on boot (no splash, just a flicker and off). My MP3 player uses a proprietary filesystem so I can't take my own songs back off the card, or inter-operate with other devices.
Eventually ended up formatting the card in my *camera* and then it worked fine. I would think they'd have provided a method to make a 'foreign' card usable.