UNO with GSM and Ethernet together?

Hi,
is it possible to use simultaneously (stacked) a GSM and an Ethernet shields with Arduino UNO ?

If not, is there any combination of Board + GSM + Ethernet which works?

I meant to build a UDP/TCP controlled SMS device.

Thanks in advance

The short answer is yes. The GPRS goes on top and the only thing you have to address is the power for that, which essentially applies irrespective of whether the Ethernet is there or not. Most of the concern is not the Ethernet per se but an incorporated SD card. The Ethernet uses SPI bus, but you call the SD with pin 4 in the usual manner. As well as pins 0,1 for hardware serial, my GPRS uses pins 7,8 for software serial, and isn't interested in pin 4 I imagine they are all much the same.

Thanks Nick_Pyner,
I'm not planning to use the SD, the idea is just to connect the device using Ethernet instead of USB, so there should not be any conflict for the SD.
What do you mean with "address the power for that"? That the Arduino UNO should be powered with external supply in this configuration because USB would no supply enough power, or something else ?

Actually I use a UNO + GSM, connected via USB to Raspberry Pi: the Raspberry reads data from Phidgets sensors and send alerts using the SMS or calls in voice synthesis via the UNO+GSM. But I would like to connect via TCP instead of USB, because I'm using a Java Tomact webapp on raspberry to control the whole, and TCP connection would be preferable to USB serial.

Thanks again

javaer:
What do you mean with "address the power for that"? That the Arduino UNO should be powered with external supply in this configuration because USB would no supply enough power, or something else ?

Something else, actually, but if you are already using the GSM, I assume you have adequate power for it. TRypical wall warts are only good for 1A and I understand the shield needs twice that for reliable operation, and hence I have not got mine going.