There are some sites like free sounds that might have some but the fastest and cheapest way is to record some. I'm not sure what you mean by "life like", but if you record yourself hitting something it will certainly be "life like".
Yeah... I've tried looking for free recorded sounds, like fireworks and the sea, and so on... but usually the quality is poor, or you can't get exactly what you need, and it gets frustrating. I think Noiz2 has a point. You could get a couple of friends over, crack open a few beers, and make a kind of wierd Foley night out of it.
The other up side to recording is you have something to trade. Professionals often trade sounds they have in their personal libraries. If you don't have a library then that is a much harder option. One of the best things to record is backgrounds and ambiance's in your area especially if your not in one of the film capitols.
I sort of doubt that those are "real" any more so than the canned laugh track. Drop some sacks of dirt on the ground, punch a few phone books, flop on a bed.