Switches are basically smarter and more powerful hubs. A router is what connects 2 networks, like your private home newtork and the internet. Hubs/Switches are what allow you to network your home computers.
almost all routers come with built in switches, just look for the 10/100 ethernet connection spec on the router, that is what tells you it is a switch also.
The DSL is what makes the phone line crackle, that's why your ISP usually provides filters to hook up to the phone jacks in your home.