I found this site
where a dude is making a MMC/SD card reader
What it does:
The 1541-III is a PIC microcontroller controlling an FAT16 MMC/SD card with .D64 files. It is connected to the Commodore via the standard IEC bus. The circuit as a whole behaves like a 1541 disk drive (therefore the name 1541-III). The MMC/SD card contains D64-files (or normal .PRG files). The user can select one .D64 file with standard LOAD"$",DEVICE commands. Once a .D64 file is selected it can be accessed like it was a real 5 1/4" floppy. The nice thing of this solution is that you can download these D64-files from internet to your MMC/SD card without the need of extra tools or cables. Because the 1541-III doesn't need to be inserted into the expansion port or require additional software or kernel it will work on every commodore computer (and even the hacked C64 DTV) that has an IEC-bus. It has been successfully tested on the following machines: VIC 20, C64, C16 and Plus4
Because the circuit is based on a PIC microcontroller and not a fancy FPGA or 65xx processor it will never act 100% the same as an 1541. This is the main reason why fastloaders will not work as on a real 1541. Still it is an affordable alternative for using .D64 files on a real commodore computer. Because things can always be better... the 1541-III is capable of upgrading itís firmware (using an PC with HyperTerminal and RS232 port). AND... since the firmware (programmed in C) of the 1541-III is released as open source software, everybody can develop new features. Or otherwise download the latest version of the firmware from this website.
This looks very interesting
should be avaible to buy from june 2006.