...

Me, no.  HPC's developers, probably.

Did you have a more specific question, or were you
just taking a poll?  It might make sense to *get* to a
more specific question, just in case the one person
who might have used HPC (or know what it is*, for
that matter) who drifts by 'once every other week' can
get to the technical question beyond answering 'yep,
I've used it'.

* High Performance Concrete?  Handheld PC?
..something to do with parallel/grid computing?

Not me personally, but people have tried / are trying.  Here's
a link to a project that seems to have been abandoned but may
help in getting started:

http://www.javagrande.org/

(I was just a bit surprised when Googling for "Java Grande",
the name of the project, actually turned up the above as the
first URL.  The ads, though, were for various coffee-related
things.  :-)? )