Replacing Cell Phone with Laptop with Internet Connectivity

easy peazy (if you are in one of 29 countries it is available in), i (at the house at least) use this

phone thing, 19.95 a YEAR (under $2 a month), plugs into any computers usb port that has internet access, and a cordless phone plugged into it/has an rj45 jack, (or under $2 for a corded phone at walmart) use it on my laptop/netbook (works with wifi networks) too when travelling (ps, one of my laptops runs ubuntu linux, bit trickier since the magicjack software is a windows program, but many progs run under linux and let you run windows programs)