OT: productivity and long computing delays

[Paul Rubin]

I'm doing something where I frequently but unpredictably (i.e. I can't
plan for it in advance) hit a snag that requires me to rebuild a large
project.  The rebuild takes a couple hours.  During that time, I'm
twiddling my thumbs and/or posting here, i.e. not getting anything
useful done.  But the delay is not long enough that I can really
switch to another project for a while.  

Anyone got any suggestions?  How do you deal with this?  It could be
mitigated with a faster computer (I'm using a 1.2 ghz Pentium M) but
the overall task isn't large enough to justify going out and buying
one.  Anyway, I did the same build on a 2 ghz Athlon 64 and was
surprised that the speedup was only 35% or so.  I'd have to get a
multiprocessor box to obtain really substantial gains.