Among my interests is telephony equipment, mostly with a focus on circuit switched (analog or TDM) equipment rather than VoIP. That said, VoIP is still interesting as an economically viable way to establish trunks with other hobbyists.
I own some significant number of PBXes and switching equipment, even if they don't all have their own sections yet: Nortel Meridian SL-100/DMS-100 w/ CS2100/CS2000, Nortel Meridian 1 Option 11c, Nortel BCM50, Nortel Norstar, Lucent Definity CMC, Cisco ISR 3845, Western Electric step-by-step connectors.
Of course, I also own a number of phones to go with those systems like various analog sets and some Nortel digital sets for the Meridian SL-100, the Meridian 1, Norstar, and BCMs.
I also have a fairly (physically) large Centigram voicemail system that I know works, but otherwise haven't done much with.
I have an Asterisk instance, like many telephony hobbyists, that acts as the main link between my equipment and the internet.
Lastly, I've got some more obscure stuff like things I've built from scratch, and a Dialogic T1 PCI card that is a nearly self contained telephony solution. The Dialogic card contains TDM switching and DSP to support a lot of functionality, you just have to program the thing yourself. There are, of course, canned DSP functions and the like which are part of the API/SDK originally provided to developers. The cards got a lot of use in voicemail systems and custom IVR hardware. Some Day, I hope to spend a little more time making that do something. A friend of mine has done some impressive hackjobs on those cards.
I list this all here so that if somebody has questions, they know that I may have some answers. Have a look at my contact page for ways to get in touch with me.