Using software to modify your Wii console's capabilities, also known as doing a soft mod for Wii, is something that many Nintendo users are doing these days. Without being unlocked, the Wii is not able to play dvds or music, imported games, or any number of things that other consoles can do.
By softmodding your Wii, you will be able to play mp3s on the Wii, play dvds on the Wii, play homebrew games and backup games, and also play import games on the Wii that you would never be able to without a mod.
Learning how to soft mod a Wii is easy and only takes about 30 minutes, as opposed to grueling hours of soldering and screws if you choose to hard mod your Wii.
Here is what you need to soft mod your Wii:
1. An SD card, purchased cheaply from most retail stores that sell electronics
You need an SD card for Wii so that you can install the softmod on it. You are going to be downloading a piece of software and then putting it into your Wii, so an SD card is required.
2. The actual Wii soft mod
This is the software you will download to install on your Wii sd card. The soft mod allows you to unlock your Wii without risking a "brick" or basically making your console unusable. That can happen if you do not follow the right steps for softmodding your Wii.
3. 10-20 minutes to install the Wii softmod
Once you have your SD card with the softmod on it, you will then place it in your console's SD slot. You will see the softmod menu pop up when you turn on your console. From there, you just follow the instructions to get the software running. It will do a quick install, and then minutes later, you'll have an unlocked Wii.
Softmods are also completely reversible in case you want to revert your Wii to its old version - for example if you have a 4.2 Wii that you want to revert to 4.1, so there are no risks.
Wii softmods also won't void your warranty, so they are simply the safest way to mod your Wii.