By now I was feeling much better about the project, and all I needed to do now was install a replacement for the Microsoft Dashboard*. One of the most popular is EvolutionX as it includes the most important feature you need at this stage: FTP access to your Xbox. Like a lot of the software you're going to need, it can be tricky to find the file you want. Some people use IRC (apparently xbins is the magic word here), and others look on torrent sites (this is how I found it). I won't provide any links, you just need to use your web skills to find what you need.

evolutionx

I found a large boot-disk image ("xbox-board.de_xbox_ultimate_4.0_Boot-cd.rar") that included pretty much everything you could want to install onto your modded Xbox, such as different dashboards, game emulators, the mighty XBMC itself and lots of other apps and skins. But this time I needed to solve the disk burning issue as this is the only way I could get the files onto the Xbox.
I tried dropping the .iso file onto Toast 7 (if you don't have Toast then Firestarter should work too) and burnt a CD-R, but then found out most Xbox's can't read CD-R disks, including mine! CD-RW was next as these apparently work much better, but again no joy for me - remember I have the crappy Thomson drive :( Out of desperation I grabbed a DVD-R off the shelf and it worked! You do need to put the disk in the Xbox and power it off and then reboot though, possibly several times. Initially I had been putting the disk in while the Xbox was on but this just produced a disk error, but if you start it from cold with the disk in it boots just fine. Back of the net!

This link has some info on what media your optical drive should support. To see what model of DVD drive you have go here.

I do intend to try Avalaunch as my dashboard at some point, but at the moment EvoX does everything I want it to, so I'll follow the principle of 'if it ain't borked don't fix it'. You can setup XBMC as your dashboard but again I've not tried that.

*In case you're unsure what the Dashboard is, it's the program that loads when you boot your Xbox with no disk in; it's normally for setting some options and configuring Xbox Live etc.