You may have noticed that the shortlinks on my posts here (which you see in my twits) are really short. I wrote this code a while ago, but I've finally gotten around to packing it up into a plugin, so now your shortlinks can look like this too.
Let me know how it works... I haven't submitted it to the plugin directory yet. Critique of the code from people who understand WordPress internals would also be appreciated.
Update: It is now available in the WordPress.org Plugin Directory as well.