Fast, easy, inexpensive spark gap?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Matt Woody Meyer by way of Terry Fritz <twftesla-at-qwest-dot-net>" <meyerml-at-stolaf.edu>

Unfortunately, time is running short for the coil project I am working on.  My 
original idea was to build a SRSG, however, due to time constraints, this
won't be 
possible (something to do this summer).  So, any suggestions for an
economical, 
easy to build gap that still will pack a punch?

My setup consists of two 12kV/30mA NST, with the possibility to add in at
least 
one 15kV/60mA NST and a few (2 or 3) 15kV/30mA NST's.  The demonstration
will take 
place outside (there is no room in our science building that is a safe
place to 
operate the coil... Ethernet + computers in every room), so I have limited
access 
to power (probably will use up almost all circuits for the HV in the coil) nor 
compressed air (I would be able to use air in the labs, but, again, not safe).

Thanks much,
><>Matt

ps: please feel free to e-mail me directly instead of the list... lots of
threads 
already open.  My e-mail is meyerml-at-stolaf.edu