Now what!? Need some advice on scintillation detectors

Hi folks!
Got my hands on some NaI(Tl) scintillation detectors to use over the summer, mostly plug and play.
Its one 2x2" and two 1x1" and now I need some nice ideas to try out. I have measured on a few sources I have and everything seems to be in order but a calibration with some well known energies need to be performed before I do any serious measurements.

Anyone got any good ideas on what I should do with these beauties over the summer are welcome to share with me
Shield one and measure downwards in my cellar or perhaps try to make a portable backpack system, but then I need a system that can sync the data with an GPS, not easy!!