To do this, you must get a program called Hamachi and vbalink 1.8beta0...
WRITTEN BY ME (almost) :mebiggrin:
1. Hamachi using guide
1. Get a program called Hamachi here: http://www.hamachi.cc/download
Hamachi let's you create fake LAN connections making you're computer believe that two computers on the internet are connected on LAN, that makes it possible play any games with LAN-only support online as well as games that need registration &/ payment to play online and so on (be aware that you only play against the people on the network but there's already many public servers on hamachi for many different games).
2. Install the program and open it, it will guide you through the basics of it.
3. Click the "Power On", it looks like a circle . It's NOT the one next to the triangel!!!
3. One of you goes to the connection button (the one that looks like a triangle) and create a new network, give it a simple name so that people don't make mistakes typing it, for example: "MMBN6" and give it a password, then click OK.
4. the other/others go to the connection button and join existing network, they will have to put the same name and password that you created, then click OK and they will be connected.
5. their IP adress are beside there nicknames

NOTICE:
- Turn off your firewall/give it permission for hamachi to connect and accept incomming connections.
- If you have more than one network disable the ones you're not using so that only the connection needed to access to the internet and the hamachi connection are on.

2. VBAlink 1.8beta0 using guide (THIS GUIDE FOR INTERNET ONLY)
1. Download VBALink 1.8beta0: http://superthamtu.yourfreewebspace.com/vbalink180b0.zip
2. Unzip it.
3. Setup all the things, like controls, save paths & so on
4. Each player opens VBALink and goes to Options ===>Link, then check the Wireless Adapter (normal Link Cable doesn't have enough speed).
5. Go to Options ===>Link again, click on "Network".
6. If you want better speed at the cost of slightly less stability, select 'Faster' on the slidebar (recommended for MMBN and PKM)
7. One of you must select Server and click Start
8. The others choose "Client", enter the IP address or name of the server and click Connect
9. When all players are connected, a message box with the text "Connected" will appear (at least it should :-).
10. Load the game and play!
11. When someone closes the emulator, the others will become disconnected.

I guess it's a cool idea to play GBA games online. Even though the graphics aren't as good as some other consoles, this feature seems pretty decent. The down side seems to be that the process to play GBA games online takes a lot of your time and effort. Also, paying is an issue for me! I wouldn't want to pay big bucks just to play online! The last downside seems to be the issue of the number of people on the website. If not many people are on the site, it's going to be hard to find someone to play against! But if there are many people then that won't be problem at all. So in conclusion, the GBA online feature does seem like a good idea, but might have a lot of down sides to it as well!

yea just to update anyone thinking about doing this now there are alot of updates to the software and there are alot better features to the software. Its really something you should look into although the legality of all this is questioned at times when dealing with gba roms.

Hi. I like your tut. Can you answer me when would you un check "Wireless Adapter" in the Link Menu

-reply by roflcopter