Last year, Alan Masarek made news as he left Google to become Vonage’s new CEO.
If you're using hosted PBX or residential VoIP, those are the only pieces of 'equipment', you'll need. If you are setting up your own VoIP phone system, you will need an IP PBX phone system, several routers, and SIP trunking/IP PBX VoIP Service. If you're using a softphone, you'll want a VoIP headset. You'll need it in order to use the softphone. You'll also need a computer or smartphone in order for the softphone to work.