My iPad does sit around at home, waiting for me to test out some new UI, but my Nexus 7 has replaced my phone altogether. I don't really make personal calls, but I do a ton of casual reading and email. While the phone is nice to have for the occasional call, the smaller form factor tablet works best for me day-to-day.

If I could use a small Bluetooth headset to make calls through Google Voice, I'd happily ditch the phone forever.