A couple of new and interesting Apple Watch online tools:
- WatchApps - an interactive look at upcoming Apple Watch apps
- Mix Your Watch - a simulator for building your ideal Apple Watch case/band combination
On the latter, I think that Apple will be releasing an official 'build your Apple Watch' app and online tool, but this site is fun for now. Also, note that it allows combinations that a) may not be available out of the box and b) don't make sense.
- Printable Apple Watch templates to get a better idea of the two sizes - link