Is land a worthwhile investment?

It can be if you speculate that this area is going to increase in value before you are willing to sell it. If growth is headed in the direction of the land you are interested in it can be lucrative, though lots of risk and growth not happening. Otherwise from my experience I dont see much appreciation in residential land. Land that is income producing/leasable land that can be a great investment.

Yes, land is a great investment if you are thinking of buying it in an area that will increase in value before you sell it. If there is growth heading that way then there could be a lot of money involved in not then it wont be worth your money or time. Also you need to make sure the land is even buildable because if not then not worth it once again.