...and what you'll pay with Ooma. You will break even in 3 months, including the cost of the Ooma box. But that's with the basic service and not keeping your home number. The "Premier" package costs another $10/month, and has all of the bells and whistles you can get from any other phone service. Call blocking, caller ID, call forwarding, 3-way conference calling, voicemail, etc. I think "porting" your current home number is another $30-40, but you'll have to pay a similar fee with any other service. Not sure what you're asking when you said "and obsolete other land-line services?" You can have all of the land-line services you wish, but certain things will cost more.

I understand why you want to change, since you're paying over $400/year for VOIP with your current cable company. I drug my feet for years before I switched, and I'm kicking myself for waiting so long.

To briefly explain how the hardware connects, you run a wire from the box to your router, then you remove your phone cord from the wall socket and plug it into the Ooma box. That's it.

Good hunting!