I have written about my making of a series of sreencasts of basic sound synthesis in puredata in an earlier blog post. The last addition to the series is the building of a patch that shows how a simple impulse response, combined with a delay, a feedback loop and a low pass filter, can be used to simulate reverberation. In fact, dependent on the settings, this patch can also be used for making phasor, flanger, chorus and echo as well. It is interesting to see how these concepts are just variations of the same thing.
The screencast is in Norwegian, but the patching is universal, so I guess it could still be interesting for non-Norwegian speakers. The patch (with some more comments and presets) can be downloaded here.