I stared using voip.ms a few years back after talk here on FT and I have to say, I freaking love it. I have 3 different phone numbers that I have finangled all kinds of different call patterns - call all my numbers, forward to this numbers, etc, etc, it's amazing how flexible it is and my phone bills run like $5 a month. It's super flexible and has lots of options and I use a client on my iPhone as well as an ATA at home. Fun to play with all the features and whatnot too, easy to tweak to your heart's content, love it.

Thanks for the update Stu, that was the one feature that kept me using Google Voice as some people just assume you have SMS on any given number and they send stuff and get no feedback as to if you received it. It will be interesting to what it's like to send messages, I just took a 2 second glance at the page and it looked confusing, may have to look a full 10 seconds to get it.