OK, well that could have gone worse I guess.
I found a bit of code, and modified it:
Browser.ExecJS("var jsontext ="& AJAX.LastData&";"
&"var image = JSON.parse(jsontext);
document.write(image.avatar_url );)")
Where supposedly that turns the string into an object with one of its key pairs being avatar_url.
That however returns an error.
Again I think my problem is what to do to get the return.
No idea if document.write is the way to go, or if I'm even in the ballpark with the json.parse.