From kli.org, the official Klingon language resource. I've known a couple Trek fans who were at least somewhat fluent. Apparently there's a whole Unicode block reserved in some fonts. Given the letter-to-letter translation from English, one could even fathom a Bash script that translates phrases using imagemagick to shoot out an image with the equivalent Klingon text.
What, don't look at me? I don't even speak it!