Yet another site for sound effects. If I remember right, this one basically catalogs all the sound files (non-spoken sounds) already on the internet and you can search by keywords for their titles. I checked it out last fall. Seemed to be a good place to find foley-type sounds that you can alter for effects. Can't vouch for sound-quality either good or bad, 'cause I wouldn't know. Very interesting visual depiction (thumbnail) of the sound file, though, and you can learn to pick or dismiss many sounds by this thumbnail.
> Before Red tells you to swing a golf club and record it, go here
A bit off topic but... Interesting how good our ears are at telling what they are hearing.
I did a title sequence a while ago where I simulated the title words being spray painted.
As a lead-in I recorded a spray-paint can being shaken. Then, I thought I could fake the spray sound just by hissing (I made the sound with my mouth). After listening to the recording of several tries, it sucked. Even with my bad ears, it sounded exactly like what it was.
Eventually I broke down, ran an air hose into the kitchen from the garage, and used a real paint sprayer to spray water into the sink while I recorded the sound in stereo. MUCH better than my first fake attempt.
Making your own can be faster than searching sometimes.