Do more with Nextel when you add a line. Nextel offers a strong set of unique features in their cell phones, and that's why Nextel is at the front of the pack for many users. You can add a line to your Nextel contract, and share that line with someone else, or you can even use the line yourself together with your existing line in the same Nextel cell phone! Adding – and using – a line could not be easier!