As more and more businesses and home users are adopting full disk encryption with pre-boot authentication, apps like this will become irrelevant. Thieves are definitely more prone to wipe the drive than they are to try to crack passwords or hack encryption.

For a locating tool to work, it should reside at the BIOS level. I believe that Dell and other major manufacturers have started incorporating products like Computrace/Lojack for Laptops into their systems.

Personally, since laptops and other computing devices have come down significantly in price and essentially been commoditized, I'd be more concerned about the loss of data on the laptop than the loss of the laptop itself. Does it stink to lose the money you've spent on a laptop? Yes, but it's a defined cost, and pretty easy to replace. How much time/effort/money would you spend recreating data from that lost/stolen laptop? Probably orders of magnitude more than the price of the laptop. My feelings are invest your time and money in realtime, bit-level, incremental online backups and full disk encryption. That way you'll have your data, and thieves won't be able to access your data.