I've just rebuilt my failing Trixbox server and replaced it with Elastix.
I found a few useful guides that I thought I might share.
This one deals with security and should be done at minimum (IMHO).
http://www.sunshinenetworks.com.au/how-to/77-securing-elastix-20-part-1.html
http://www.sunshinenetworks.com.au/how-to/86-securing-elastix-20-part2.html
This is also quite handy. It takes me back to the Trixbox without tears days :)
http://sourceforge.net/settings/mirror_choices?projectname=elastix&filename=Tutorials_Docs_Manuals/Elastix%20Without%20Tears/elastix_without_tears_june2010.pdf
Feel free to share your guides, security hints, and tips.