Ive been searching through the forums and it seems this comes up quite a bit; How does one access the SDcards?

I know Craig said in the 8-bit computer forum that he had some success with them; in another post somewhere I read they were interfaced with the SPI protocol, and indeed in the datasheet I am looking at now it does mention SPI. Therefore, I have some
questions I hope someone can explain :

1. Is it possible to access the cards at a "low level"; IE : No filesystem. If so, I assume the cards cannot be read from in your standard card reader. Any suggestions on transferring this data to a windows PC?

2. When using a filesystem, I have read that the cards are very slow to write - that they must update the FAT every 512 bytes. Is this true, and would it be possible to skip updating the FAT until the end of the write process was completed?

3. I've seen links to projects that have used AVRs to do this; but for the most part it seems as if there is along of "finger pointing", that is everyone has links but nobody from these forums have actually done it.

This is for the beforementioned digital recorder I am designing.