COMMUNITY : FORUMS : BURNING QUESTIONS

I have seen a few different laser trip wire instructables here, but they are usually for triggering a nerf device or other projectiles. I am interested in a laser trip wire that would count objects as the laser beam was broken, and display the count on an LED screen. I was wondering if someone would be kind enough to create an instructable for this. This has real world applications, such as counting cases moving along a conveyor line. I would like to use an arduino with a shield for this, and be able to plug it into an outlet. I am a complete Noob when it comes to arduinos. This is a project that I would like to get my feet wet with. I learn best by working on something that interest me. I know it isn't as much fun as a nerf Gatling gun, but it would get plenty of use every day.