This is something I that I thought would make for a fun (and geeky) public art sculpture: the severed head of a Sentinel robot from the X-Men comics. It would be neat in a public park, however I feel it would be very much at home on a university or college campus as a nod to the Xavier Institute.
In all honesty I doubt any city or school would permit such a geeky art installation, so I think this would be a neat prop that could be parked at comic conventions. Cosplayers and geeks could get their picture taken with the fallen robot, which would be a pretty cool keepsake.
This art installation/show prop could have lights in the eyes, which adds a bit of flavor. The Sentinel could blink back to life momentarily or stare angrily for prolonged periods of time.
Maybe that fella who built the life-size Skeletor could make this?
If you dig this please check out my take on geeky landmarks.
One last thing: the Sentinels have to be in the new X-Men: Days Of Future Past film, right? That would be awesome.