After searching the "net" for DLNA servers I ended up with going to /usr/ports/net/serviio and made an "make install clean".
After alot of dependencies was installed I finally added the magic words to rc.conf:
serviio_enable="YES"
serviio_args="-Dserviio.remoteHost=yo.ur.local.ip" #change to your IP
and fired serviio up.
OK. It started?! Now what? Well, this is the ceavat of serviio. You need a GUI. So download Serviio from http://www.serviio.org/download and install it on a client (I choosed Ubuntu 10.10) and start serviio-console.sh.
That did not work for me. I needed to add this line
-Dserviio.remoteHost=your.ser.ver.IP"
at the end of the "JAVA_OPTS" line in the serviio-console.sh.
Then the console started and found my serviio server. From the console it is straight forward to add paths for your media.
I tested it with XBMC in ubuntu 10.10 and it worked great. I can browse the content served by the Serviio server. Going to test it tomorrow on the TV.
Happy surfing!