I think the average golfer can get great benefit from a GPS device. The new wave smartphone applications will not just give you a yardage, but will keep important stats like driving distance, greens in regulation, fairways hit, and total putts. They are getting so advanced we'll soon be able to play the hole without even looking at it.
I still like the traditional way though. I grew up learning that one pace was one yard, and I practiced by walking out 100 paces and hitting wedges to a shag bag. I grew up on my paces and I trust my own yardage and have a swing geared to my personal yards. I understand, if used in the proper fashion, that GPS and laser range finders speed up play. However, I have also been ready to play before some players even get the yardage from their device because they have to wait for the GPS to catch up, or the wind is too strong for the laser range finder.
I have seen the positives and negatives of both methods, and feel they help my game. The worst thing we can do is guess, and no matter what, we should always have a routine to get a proper yardage. I encourage you, if you have a Smartphone to download the free application below. If you already have a GPS system, let me know how it's helped you. If you don't, follow the link and give it a try for your next round.