Nintendo have released a new drive in the latest Wii’s that currently cannot be cracked. The options are replace the drive or use an alternative method of loading games such as SD card (offered by the WiiKey Fusion) however this can be expensive considering the cost of SD cards.
EDIT: There is another alternative now which is the WODE (Wii Optical Drive Emulator) which emulates the optical drive and unlike hard or soft mods can never be detected.
The WiiKey Fusion Wii Mod Chip can be found here
Modsupplier @ AUD$72.50
The DriveKey Wii Mod Chip can be found here along with info on the new dvd drive
Modsupplier @ AUD$59.50
General info on modchips can be found on Wikipedia here – List of Wii drivechips
The Wiikey Manufacturer website has plenty of information – Wiikey