I've found this to be quite educational. The idea is to pick an inanimate object (nothing larger than a man or smaller than a cat, say) and photograph it every day for a month. The photos should differ in as many ways as possible, in terms of composition, lighting, camera settings, focal lengths, perspective, and such. One variation that I found interesting was—at the suggestion of my flatmate, Brian—to try and keep the object the same size in the frame while altering the focal length. This really gives you an idea of how longer focal lengths compress perspective.
At any rate, it's quite fun, and you can get a lot out of it. Here are some unexciting images of a traffic button:
![Image](http://farm2.static.flickr.com/1033/769998639_bd254df69a_s.jpg)
![Image](http://farm2.static.flickr.com/1327/769998603_d5bad6ccb5_s.jpg)
![Image](http://farm2.static.flickr.com/1164/769998583_c2f54ea37d_s.jpg)
![Image](http://farm2.static.flickr.com/1414/769998557_6e95bf08ae_s.jpg)
![Image](http://farm2.static.flickr.com/1318/769972869_0dbad39ccd_s.jpg)
![Image](http://farm2.static.flickr.com/1069/769972795_789ae11f11_s.jpg)
![Image](http://farm2.static.flickr.com/1119/769972781_cec658c0a8_s.jpg)
![Image](http://farm2.static.flickr.com/1126/769972757_bf8097007a_s.jpg)
![Image](http://farm2.static.flickr.com/1420/769972699_95aba04e26_s.jpg)