A couple of things about survival should be taken into consideration before we talk about whether stone tools are viable for you. The essentials in order: 1. Shelter 2. Water 3. Fire 4. Food. Before we start another thread, I know some of you think water is number one, but lets not go there now.
Does shelter require a cutting instrument? No. Does water require a cutting instrument? No. Does fire? If you dont have a lighter, matches, or something that creates spark and you have the skill to make a bow or hand drill, then YES. And obviously, food requires a cutting edge, for trap making to cleaning animals.
So to answer your question, if you know how to make fire using primitive methods, you might as well as take it one step further and at least learn to make a cutting edge out of rock. For cultures and those purists out there, stone tools rank as the silent # 3 next to fire in the order.
Yes you can find flint, chert, shell, and/or coral just about anywhere. All can make a cutting edge. Obsidian is volcanic rock and can only be found in certain areas of the Rocky Mountains here in the U.S. Obsidian is very desirable for flint knapping as it is very easy to work and can be sharper than any steel. If fact it is sharper than they can make any scalpel, thus it is used in special surgeries.
I suggest looking for rock with high glass content and breaking them with a hammer stone until you get a sharp edge. It doesnt have to be pretty or symmetrical, just sharp. A hammer stone can virtually be any rock. And to check for high glass content rocks, bang some together and listen. The higher the pitch, the more glass.
You can read books and search the web to learn how to make arrowheads but that is tough. I have heard videos are a good way. Or you can do what I did and look for a knap-in in your area. Buy a kit and some rock from someone selling there and ask them to get you started. They will be happy to make another convert. And dont leave until you make your first arrowhead.
Personally, I like having this skill as it gives me a comfort level with where I am in life. I can also tell you flint knapping is a kin to whittling when it comes to relaxing. However, it is also the original blood sport, as you will get cut.
Hope that helps. Here are some good links:
http://www.nativewayonline.com/
http://www.earthskills.net/main.htm
http://www.flintknapping.com/index.html