When we were setting the piers for a new deck, a friend brought over his Black & Decker rotating lazer. I think they sell for about $150 at HD or Lowe's. It comes with a case tripod etc. I tried it out inside the house and it worked great ... absolutely magic little toy. Outside, in bright sunlight, was another story. It was just too difficult, almost impossible, to see the lazer line even with the glasses on. Maybe a lazer detector would have worked but we didn't have one. We had to revert to the ol' string method which worked just fine.
Perhaps a more expensive, higher intensity lazer would have worked better outside but for inside work I think it would real timesaver and besides ... it's really neat. I know that I love my lazer torpedo level and $40 Sears lazer plumbline/level but again they work best for inside projects.