Laser levels are great. Mine has saved me innumerable hours and allowed me to get noticeably better results for certain types of projects than in the past. The self-leveling feature, in my opinion, is really important. For example, I was using my level to establish the top level for a very long exterior retaining wall that needed to be flat within +/- 1/4". By putting the level on a tripod, I could swing back and forth along the whole length and make sure it was all level. With a laser that depends on a bubble level, you have to keep fiddling every time you move it or pivot it. With laser levels, you have to pay more for better features, more accuracy, and higher visibility, and it's easy to spend a fair amount if you don't want to compromise.

To educate yourself, get hold of the current issue of Fine Homebuilding (January 2007), which has a multi-page, illustrated article/review on laser levels that compares features, costs, etc., and will probably answer every one of your questions.

Thanks much, especially for the Fine HomeBuilding tip. I'll take a look.