Here is a brief analysis from the freewordlicence.org of the two licences.


BSD Licence:
  Has a No warranty clause and says that the original copyright notices 
  on the software must be retained, but otherwise lets the user do what 
  they like with the software, including creating proprietary commercial 
  versions. 
  http://www.opensource.org/licenses/bsd-license.html

GPL - Gnu's Licence.
  This is the gold standard of free software licences and apparently has
  over 60% of "market share" (i.e. 60% of programs released under free 
  software licences were released under the GNU GPL). This licence provides  
  strong protection against the proprietarization of the software and 
  addresses issues such as patents and commercial distribution for a 
  copying fee. If you want your software to be free, you should start with
  this licence and see if you can come up with a reason for changing to
  another licence. 

More on LICENSES:
 http://www.freeworldlicence.org/other_licences.shtml