Cheers for the lead on Screenshot Captor Tom, it looks like a very handy tool but it's not exactly what I'm after.
I have actually used (in the past) a tool which is very like a text box but instead you can pick a banner or scroll type object and use it just the same as the text box. Once you've finished entering your text, the text is then left within the banner etc. I just can't remember which software it was that I've used in the past???