I'm about to start on a plugin that has a fair number of tentacles... although I'm experienced with PHP, it's my first WP plugin.
Looking for a solid example that covers some / all of these areas:
* creates / maintains its own db table
* has its own input fields on the post page (a la custom fields)
* client side can call into the plugin to get data (via XMLHttpRequest)
* doesn't require any hand-editing to install
I think Owen Winkler's Geo plugin looks like a good reference, but would be happy hear of any others.