Oh, as a way using UVMapper, select the faces you want to have a tile. Then maximise them (press '=') so they cover the entire screen. Now press '*' on the numeric keypad to double the size of the selection and it will tile twice. Double it again and it will tile four times each way. And so on. Of course, this only works for powers of two, but you can nudge it up using '+', though it's hard to make it even this way.