New to the Tivo world, I'm looking for some tips. I did my initial setup at another location (for the phoneline) and have now brought it home where I have no phoneline, just a broadband modem. First off, is it possible to update the system w/o a phone line? If so, how do I do it? Here's my setup: Comcast modem; Mac Airport for wireless; Tivo unit starts w/ 540. Can I simply buy a usb (like the tivo one) and be off and running? Thanks!