If you want to organize your Wii's SD card files without having to take it out of your console, then you might want to take a look at developer miom's homebrew file manager for the Nintendo console. Entitled "SD Explorer", it allows users to make use of all the basic file managing tasks straight from the homebrew application's interface.

The latest release of SD Explorer, version 1.0a, fails to mention what new changes were added since the previous build. However, it's better to be safe than sorry, so you might as well update to this latest version in case you still have version 0.9 installed on your console.

Some of the upcoming improvements the developer will be working on include a copy function, as well as a dol/elf homebrew loader. It was also mentioned that there are still currently some bugs linked to the delete function. Deleted files don't get back the released space. This will also be something miom will be looking into in the next version.

To install SD Explorer into your Wii console just copy all of the contents of the archive into your SD Root. Please make sure to extract all the files since doing otherwise might crash your Wii.