Need examples of 'blocks'

I read the howto on ‘blocks’, however, since I’m sort of tuning into
GNRadio applications, are
there examples of something like the following.

scenario 1:

Taking data from USRP, performing an FFT, then performing some
‘Algorithm’, then
passing the results to the windowing processing to display results in
graphical form.

scenario 2:

Take previously saved FFT data, passing through the Algorithms block,
then to the graphics.

scenario 3:

Take either ‘imput’, and pass the stream through the Algorithms block,
and save the raw
results to a file rather than the graphical output…

Had I tuned into this project earlier… this would have been the
approach… however, I’m
inheriting a project… and would like to see if there are examples that
would help me
put things together quickly…

John C…