Web based IP Address Management software. There are a few out there, most of them dead. Some are add-ons to bigger projects (NOC Project, Infoblox,) or doesn't work like I want (GestióIP), or cost too much for us (Solarwinds). DB backed with auto-discovery and a useable web interface. I use NOC, but most of it is wasted since I don't use any of it. Mostly just the IPAM stuff.

I have multiple addresses. The Yahoo one, that I got when they started up. My main personal address which I've had for about 5 years. Then of course the other oddresses; the dedicated spam address, the one I never check, the hotmail one (which is another spam hole), and a few others I don't remember I have.