Mauro Bergumasco has played as flanker, centre and scrum half for Italy (or was it Mirco?). George North is big enough to play in the pack.
Most that I can think of would fit in the back row like for wales Jamie Roberts as 6 because I have seen him carry the ball of 9, Jonathan Davies number 8 as he is brilliant at line breaks and Mike Phillips as 7 Forwards that can play in the backs are Keiran Read, Toby Faletau plus a lot of opensides
Jamie Roberts as flanker, Mike Phillips as a N8, Twelvetrees as a lock, Richie gray as a centre. That's all I can think of at the mo.