What are practical applications of AI Planning?
[In the following, I am providing links to some events in 2011/2013, but you can find much more looking for previous years]

By AI Planning I assume that you mean Automated Planning (STRIPS, SAS$^+$ and so on) instead of path-planning and other problems more tightly related to robot navigation. If this is the case, SPARK is the right forum to look at. 

Other practical applications are often discussed at the main track of the conference ICAPS. A couple of examples:


Maria Fox, Derek Long, Daniele Magazzeni: Automatic Construction of Efficient Multiple Battery Usage Policies. ICAPS 2011
José E. Flórez, Álvaro Torralba Arias de Reyna, Javier García, Carlos Linares López, Angel García Olaya, Daniel Borrajo: Planning Multi-Modal Transportation Problems. ICAPS 2011 (admittedly, I am adding here a reference of my own, beg your pardon, I did just because it was easier for me to locate the reference).


Hope this helps,