The first six lines come off my asterisk server, all the same DID number, in a hunt group, so if line 1 is busy, it rolls to line 2 and so on. 7&8 are some google voice lines, 9, is a fax line, 10&11are C-Net lines from the collectors network, and 12 is the Comcast voice number that nobody uses.
A handful of extensions are the usual things, phone in the kitchen, bedroom, office, garage, that sort of thing, with actual Euro I & II sets. Most of the rest of the extensions are to bring some of my vintage and antique phones to life, though I'm slowly migrating them to the channel bank hanging off of asterisk. The migration isn't overly difficult, its just a little tedious. Asterisk isn't the most user friendly thing.