For a basic logging application where all you want to do it write data to an SD-card I'd suggest you take a look at the OpenLog project. It originates from Sparkfun (and they're selling it) but you can find it on EBAY for a couple of bucks. Stick an micro SD card in the socket, connect it to the PIC and throw ASCII data it at 9600 baud (default setting) and it just writes it to a text file. You can set it up to either append data to an existing file or create a new file each time it boots. There are provisions for Reading files as well but I have not tried it and I don't know how userfriendly it would be to do with a PBP.

With that said, I'd love to get an SD card working for reading/writing so I can possible do a SD-card bootloader etc.