Yes & Yes
There are a number of "good" services out there for home.
Big things to watch out for:
Smaller (read: fixable) things to note:
- Vonage, in particular, and many other services will let you port your number to them, but will not release your number once they have it. Be sure you're happy with any service before you port your number.
- VoicePulse (using them currently) has a great product. Their marketing is abysmal, as is their documentation. However, it works beautifully over Comcast. I understand there are some issues if you have DSL service.
I picked VoicePulse primarily because they offer phone numbers in my hometown rate center. That way, my parents can call me without paying for it. Only VoicePulse and Verizon offer local numbers there, so my choices were limited. VoicePulse also does some neat pony tricks like ringing my cell phone selectively based on who's calling, prompting callers to press a button if they really want to talk to me after 11:30 at night, and importantly, <30 seconds failover to my cell phone if my Internet connection goes down.
- Some products (like Vonage) provide a router/gateway that goes upstream of your home router. This is nice in that their product handles QoS to ensure voice is always top notch. However, in practice, the devices appear to need a bit more firewalling, as they will lock up when they see Internet traffic they don't like. In practice, you'll need to set your Vonage gateway inside your home router to keep it reliable.
- Products that sit inside your home router will exercise your router in new and exciting ways. If you're router has never locked up or spontaneously rebooted before, it probably will when you add VoIP to the mix. I had to pick up a second Wireless router to separate routing tasks from Wireless as the DLink unit I have wasn't up to doing both.