Well I'll go you one better. Some very clever person managed to port the entire SFXR app to ActionScript, and a very faithful knockoff of the app is available entirely on the web here.
Best way to test it out is to click the buttons along the left column a few times each. Those randomize the settings within a constraint that sounds like the effect the button describes. Once you hear something that's reasonably close, you can save out the sound as an SFS file (which is just the settings of all the sliders) as well as a WAV file that you can slap into your project.
Or you can just mess around with it. I like to press the "explosion" button, then press the "mutate" button a few times. This never fails to awaken long-dormant neurons that have been sleeping since the Atari 2600 days.
Enjoy!