It depends what type of barcode you want to create.
IDAutomation offers a free code 39 font. If you are looking to use something like Code 128 or Interleaved 2 of 5, the fonts are not free but IDAutomation offers support to help you get integrated with Crystal Reports, and they have a few different options for integration too, so you're not just stuck with one method.
http://www.idautomation.com/crystal/
Edited by MHorton - 23 Sep 2008 at 12:04pm