One of the new tools is the Kellycraft Get It Straight Laser Square. At first I thought it was sort of whatever, but after watching a video (or two), I'm totally sold!! I'm definitely ordering one in my next order.
I know it looks like it would be primarily used for scrapbooking, however, I think it would be quite useful for cards too; for things like adding brads or Candi all in a row. Or to line up a stamp so it's straight too.