Yeah, I've got the same options as Ace. I'll read through that tutorial and see if I can find anything. Thanks.
And... Jabba just posted

. All mirror does is reverse the entire texture, whereas I only want half of it reversed. Would it be easier for me to just post the pic of what I need to do?
Edit: Well, here's a pic anyway:
So what I want to do is flip it so that the left side of the polygon has what you can see now, but the right side of the polygon has the same image, except reversed. Having looked at the editorial you posted, it's useless for that particular polygon because, being a square with only four vertices, it cannot be split in half. So the only way I can think of now (and which would work with your method, Jabba) is to split the polygon in two (using the Add Edge Tool), and then UV map them separately. The only problem I can see with that is that it will be difficult to get them to line up properly, but I'm sure I can do it

. Thanks guys!
Edit2: LoL, it worked! Problem solved, and thanks for all your help

.