I don't really know your girlfriend so I have no clue what her likes and dislikes are. So..yeah. If your not too serious, and don't want to spend too much money ($150 is a lot. Well to me it is). Get her a nice cardigan sweater. With 150 you can probably get a nice cashmere one. If she doesn't dig sweaters, get her something for her room. Or better yet, get her a polariod camera. Every girl I know either has one, or would kill to have one. :)