Twilio Elastic SIP Trunking is a way to connect SIP gear to the world through Twilio, offering scalable and resilient connectivity with transparent pricing. To get started, users need a Twilio account, FreeSWITCH installation, and a registered SIP endpoint. The process involves gathering information, securing the project, provisioning a Twilio Elastic SIP Trunk, connecting FreeSWITCH to the trunk, and configuring dial plans. Common gotchas include firewall settings, dial plan location, inbound calls, and Access Control Lists. With an Elastic SIP Trunk working on their FreeSWITCH install, users can explore additional features such as recording, international dialing, and conferencing.