This reminds me of that Simpsons episode where Homer goes back in time and steps on a bug, resulting in changes in the future. Only it's the present. Or is it the past, and smooshing that bug you saw caused changes in the future?
That tarantula story has been going around the internet in one form or another for as long as I can remember. The most popular variation has a lady poaching a cactus in Arizona and taking it home and putting it in her living room. She notices the cactus is moving slightly and... well, you know the rest.
Here's one I hadn't heard before, circa 1992. (from the snopes site)
I've looked at some pictures of different types of assassin bugs and I really think that it was a type of assassin bug. I'm not sure if they are native New Hampshire though so I might be wrong on that, though it really did look like one.
Stings are far worse than any wasp/hornet/bee/scorpion, and can take months to heal. I know, because it's happened to me. (No it's not a spider....we all know about them..)
I was out playing golf, and one happened to land on me and stung me on the stomach. 6 months later, I was healed. But the pain was unbelieveable. Check it out.
DavidMich: That's pretty much what the insect I found looked like, except it was a little more round and greenish. The head was exactly the same though.