Tom Hume's blog has a very interesting new entry on a virtual pet environment built for Nokia cellphones, and called Twitchr. Hume explains that in the game, "...digital birds visit your mobile phone. An application that resides on your handset gives you a window onto a "virtual garden", into which these birds will fly from time to time. To tempt them, you use an almost childishly simple one-click interface to drop pieces of seed on the ground; minutes or hours later, your handset flashes and tweets as a bird arrives, and you have a short window of opportunity to click again and snap a photo."

There's also further complexity, both local ("If you configure Bluetooth and "pair" your device with that of a Twitchr-playing friend, then birds can fly between your phones") and worldwide ("Once you're online, your phone becomes part of a massive digital environment: numbers of the various species rise and fall over time, new species can be introduced, and old ones become extinct.") Oh, and its name is a Flickr-inspired riff on a 'twitcher' - effectively an ornithological trainspotter.