Foursquare: Great social network or creeping device?

Okay, so I decided to hop on board the social network known as "Foursquare" finally. Being a devout Facebook and Twitter user, I had seen friends posting from Foursquare to these sites telling me where they were and what they were doing. At first glance, I assumed that Foursquare was just basically a glorified Facebook check-in app. However, after I downloaded and began to use this, I realized that there could be some great advantages and disadvantages to this.

Basically, whenever you go to a bar, restaurant, or any place of interest, you can "check-in" to it and tell people you are there. After the initial check-in, you gain points based on the location, how many times you've gone, and how many of your friends have checked into the same location. If you accumulate the most check-ins at a spot, you become the "mayor" of it. I found a bar where if you became the mayor, you would receive happy hour deals at ANY time you visit. Pretty sweet deal if you ask me, I could eat a massive plate of $5 nachos and a massive $3 margarita any day. It also seems that Foursquare has worked out some deal with American Express, as most places offer a deal through them stating that if you spend $10 through AMEX, you get $5 off. Aside from being the mayor, anyone can leave notes about a location. These can be really handy if you've never been to this place before, as regulars can leave inside information regarding deals or specials. Again, another way that I've found this social network to be helpful, I'm always down to save some money when possible.

What worries me is the fact that when you check-in, everyone knows exactly where you are. If you checked into every place you visited for a week, someone reading your feed could literally follow you around. It's almost like having some creepy friend looking over your shoulder at all times, updating what you are doing to the rest of your friends. If you're trying to avoid seeing certain people, Foursquare is definitely not going to be the social network you want to be using, stick to Twitter and not checking-in.

Basically, I see this as a mixture of savings and stalking, with a side of actual social networking. I haven't been apart of this fad for too long, so I'm curious as to what some heavier users of Foursquare think about it.