Reducing Facetime camera resolution

Now why would anyone want to do this? Don't we all want brillilant, sparkling, hi-res video? Usually, yes. However, when connected to a public network, for instance in a coffee shop, the wi-fi connection can be less than excellent, and being able to reduce the bandwidth required would be handy. If you're on an iPhone (or in my case iPod Touch), you only have a small display anyway and you really don't need 720p in such cases. This would be a useful feature on OSX as well, to reduce the outgoing bandwith from an otherwise HD video camera when connecting to someone in a location with a poor wifi signal.