Yesterday, I decided to toss the source of my first real XPages app up on GitHub:
It's my WoW guild's web site, which had some forums as well as a raid-management tool and loot tracker. I'm guessing that those tools won't be particularly useful for your average XPages app, but they were interesting things to build, and were a great exercise in figuring out the platform. Since it is quite old, there are also plenty of terrible decisions in there, such as my mass recycler from before I knew that Domino objects are already all recycled at the end of the request, but hey, that's growth.
In any event, it's there for the curious, or in case any of the code ends up being useful for future Googlers.