I'm sounding like such a complete ding dong head it's embarrassing.
I've made a couple of text brushes, and I have installed them in my PSP7 and they work fine. I have no idea how you get them onto a site though.
In PSP7 there is no opportunity (or so it seems) to call your newly made brush anything. It just says it's an Ubrush. In my brushes folder, I can't find any of the Ubrushes I have made, so I don't really know what I'm going to do about it.
Any ideas?