The purpose of this instructable is to serve as a suppliment to anyone out there that has either soft or hard modded their Original Xbox (read: not the 360). Some parts also apply to Stock (non-modded) Xbox as well (in the case of XBConnect). This will allow you to enjoy your Xbox more fully, and as well you can learn a few tricks and maybe even make some new friends.

Step 1: FTP and What It's All About and How It Can Help You!

The short, sweet, and simple definition for FTP is File Transfer Protocol, which allows you to have a simple way of transferring files between computers (or in this case, an XBox to your PC and back). With this being said you should get yourself a few essential materials for this.
A Crossover Cable (cheap and can be found at most electronics stores or made if you have the gear)
An FTP Program (i use Flash FXP but whatever flavor you like works)
A modded XBox (mine is softmodded with the tutorial that i published)

If you have XBMC installed as your Dashboard, you can find out your XBox IP address in the settings section (once you have connected your XBox to a PC via Ethernet with a Crossover cable). After you set it to be online (not hard trust me.. if you soft modded your XBox you can do this part yourself). Then simply open your FTP program, then in the section that allows you to set a connection, simply enter the IP address from the XBox (write it down and stick it on a post it on your computer), then enter in 'xbox' for username and password (that is the default UN and Pass for the Xbox). then its a simple matter of transferring the files from the directory on your computer they are saved on to the are on your PC to your XBox they go to usually on the E Drive (under the Dashboard folder for softmods). Then you can load the files in the corresponding subfolders (usually under Plugins, there are ones like Video, Audio, Programs, Emulators etc). You can usually find some of these folders in forums and with simple Google Searches.

Step 2: Sharing Media With Your PC

If you are like me and cannot STAND to watch movies on your PC and perfer using your Television, then you will like this section! The crossover cable has another advantage that allows you to share/stream media from your PC to the Xbox using the Workgroup (SMB) section of Video on XBMC. all you have to do is just make sure that your XBox is connected to your PC via Crossovr cable, that you have a small network set up (using the Network Wizard in Windows is so easy that if you cannot do it then you should not have a pulse.. just kidding but the pics below will show you how to do it easily under Windows XP). After this is done, simply right click on the directory that you wish to share (i shared my entire external 300 Gig Hard drive that i store all my media on (C drive is programs only for me) and then simply click under Sharing/Sharing and Security (depending on what operating system you have). Then all you have to do is go through the motions. The Workgroup name that you set in the Network Wizard will come up then when you select WORKGROUP in the Video menu in XBMC. After that, just browse away and play!
Note: XBMC for Xbox will play most any format you throw at it, but High Definition Video under the H.264 container is pretty choppy and problematic due to the memory limitations of the Xbox.

Step 3: Playing Against Others Using System Link Games!

Ok.. anyone with a bit of search engine skills will have learned that any modded Xbox will get the big dirty eternal ban from Xbox Live! But fret not! there exists alternatives! Until recently, there was a program plugin for XBMC that ran internally called Xlink Kai. But due to lack of Ease of Use (imho) it was terminated. But a rather good alternative (and is used widely by many in countries where Live is not avaliable) is called XBConnect. XBC is a client used by anyone with an XBox or 360 (and some PSP users) that can play games meant for LAN parties (Halo 2 anyone?). Simply install the client (the free one will suffice) and then simply set up your account on it and log in. then when you connect, it will display in the client window a listing of Game Filters for games such as Halo 2 or Mechassault (pretty much any game that was System Link compatible). all you have to do is on your XBox:
start the game and then go to the System link screen (and log into your profile, like in Halo 2), then simply go on your client and then under Tools in the menu, have it detect your console. after that all you have to do is click the room of your choice under the game you are playing (staying in System Link mode on the XBox) and you can still play against people from around the world. You can even use your Xbox Live Communicator Headset on there to talk smack to your opponents. but i do no condone teabagging! One interesting note is that many from South America frequent this system as Xbox Live is not avaliable there.
Note: you do NOT need a modded system to play this, but you CAN use backups to play on here (i tested with a backup of Halo 2)

Step 4: A Few Notes (appendices)

I do recommend that you use the Xbox remote for all the media functions of your Xbox under XBMC. You can find them online new on sites like Amazon or in some Big Box stores or even second hand and Video Game Resellers like EB Games. As well when you have the science of FTP down, and u can transfer some scripts (just like plugins but a little handier) it is a good idea to install T3CH Easy Installer that will allow you to update your version of XBMC without having to bother with FTP and complicated steps. I use and highly recommend it. As well, signing up to some forums can be helpful for support and some useful programs and plugins as well, like the Family Guy and GameTrailers video plugins (nothing like the entire run of Family Guy as well as The Angry Video Game Nerd without having to sit in front of the PC to watch it!). I welcome comments and suggestions!