Gas Law Experimental Apparatus
Some of the things you have at your disposal:
Besides the normal Vernier LabPro, Laptops, LEGO NXT, etc.
Vernier Gas Pressure Sensors
Vernier Direct Temperature Probes
Go Temp Temperature Probes from Vernier (USB plug)
Vernier Stainless Steel Temperature Probes
Here are some links to the Vernier Site with some suggested experiments:
Based on the above, you should be able to also figure out a way to vary volume vs temperature.