I currently have an arduino which I would like to attach a gprs shield, motor shield from seeedstudio, and a camera. Can all of this be done from stacking shields together or would I need more devices?
Take a look at which IO is used by which shield, see if there is any pin conflicts.
All device can share SCL/SDA (I2C), all devlces can share SCK/MISO/MISO (SPI) but need unique slave select pins.
GPRS, Motor may need external power connections as well (I think they might have their own connectors for that).
I'm working up a "wide shield" to allow users to connect IO pins as desired to multiple shields as well - search forum for "wide shield" to see some views.