There are two new Linux Bluetooth applications from the trifinite.group, both are not really security related but very useful.

sobexsrv - the scripting (secure) obex server
an obex server with support for plain obex push with put and get and obexftp further it supports Bluetooth security mode-2 (application triggered security) and is fully scriptable, this means server responds can be user controlled, so one can build all kinds of applications based on sobexsrv

btslides - use a bluetooth headset to navigate a slideshow
a simple tool based on Marcel's epox-presenter application, it basically converts the volume keys from any generic bluetooth headset into X11 key events, nothing exciting but handy for those of us who do give a talk everyonce in a while

Both tools are still under development, so feedback is welcome.