To clear a little confusion, BuddyFinder and LiveContacts are two sort-of related names for the app, which is itself the free branch of the better-known FindWhere, a Dutch company with a much more useful, robust service--tracking people down (kids, an elderly parent, a wayward spouse) through their devices. FindWhere includes lost phone recovery, emergency alerts, and notification services if the device goes outside your specified bounds.
Of course, the free BuddyFinder doesn't do all that. Instead, it installs an app to the phone (with yet another name) that utilizes either GPS or cell phone triangulation on select smartphones, and broadcasts the location to FindWhere's servers. The app's only role is to play transmitter. Buddies then see your location mapped online after every five minutes or location change. That's wonderful for plotting a route somewhere for demonstration purposes, or to prove that you actually did go to the library to study, but it's less useful if you're interested in finding a pal while you're out and about.
From the looks of it, BuddyFinder is a rather late, rather feature-slim arrival to location-based friend tracking that's similar to a lot of other services out there, including Loopt, Whereboutz, , and even FindMe, which didn't impress me on all accounts, but works nonetheless.
To differentiate BuddyFinder from the competition, the press materials call the Web and cell phone app combo "the only truly free buddy finder service on the Web." I see what they're getting at, since some of the other services rely on data transfers to update your location on your phone, where BuddyFinder tracks you from your PC for free. As I mentioned, it's hard to see how being limited to the PC is a perk, even if there is no data charge. Besides, much of the audience for location-based services already subscribes to an unlimited data plan, so it's difficult to see a real detraction there.
Still, if you're seeking a geo-tracking service, there's no harm in looking at BuddyFinder. You can sign up for the beta now, or wait until April 15th for the full release.