Google Voice is probably the best service that google has, which is quite the statement, but I still think it is true. The basics of google voice is that you get a new number and it redirects to whatever phone you want, and passes your texts to your phone too. It has some really cool features like transcribed voicemails, choosing a time of day not to be disturbed and being able to block people you don't like. Other cool features are things like the widget that I have on the side of my page here, where you can call me without actually knowing my number. My favorite use of it is giving out that number on craigslist so I don't get calls for the rest of my life.
Since getting google voice sometime last year I have been trying to do something good with it, especially text for free on my iPhone, or even call over VOIP using it. As of today I can do both.I have been trying to text with Push notification on my iphone for a while, and until today I have used apps like TextNow Lite or Messagey which did let me get Push notifications, but I could not respond. I would have to then open the gv web app and respond from there. It got annoying. I have a work around, it isn't the coolest ever, that would take jailbreaking my phone, but for those of us who want to be legal, her is what I do. You will need an app called Meebo and a google talk account (which you have if you have gmail, even if you didn't know you did). Go to the GVMax web site and set it up. GVMax will do a lot for you first, and most importantly it will forward all your texts to a your google talk messenger (as long as you had click the option in google voice to have it send texts to your email.) Now open up Meebo and sign in with your google talk account. I choose Meebo for two reasons: it has push notifications, and it pushes forever, no auto-logout ever. This is important if you want to use it for texting. Once you have that all set up you can text for free forever, as long as you have internet. (This work with an ipod touch and wifi.)
One thing that a lot of people want with google voice to make VOIP or SIP calls. There was something called Gizmo5 which made it simple and work. Problem is google bought the company and who knows when it will be released again. I will give an update when it is re-released, but till then I have a work around. Remember this is a work around, so it isn't the best, but for the time being it works. So a few days ago I stumbled across this web page that tells how to set up a number for incoming calls using PBXes.org and IPKall. If you follow that tutorial you will end up with a new phone number that receives calls. If you have an iPhone this is great, just download an app that work for SIP calling and set that account up. I have tried NimBuzz and Fring. I use Fring because it worked better on my phone, but the setup is about the same on both.
The tricky part of the whole process is for outgoing calls. This is when once again GVMax helps us out. Nimbuzz and fring let you log into google talk so you can use the chat thing I told you about before. There is an option for GVMax what when in a chat with someone you can type ggc and it will call that person. There are more options which GVMax has, but the chat inside the app that makes it possible to have it wall work, and not need to multitask (iPhone's biggest flaw).
GVMax also does something that I have been try to do, mass texts through google voice. Google Voice blocks you to only text 5 people at a time, to stop you from using their service to spam people, GVMax goes around this. It uses google's contact groups, and text to an entire group, using their cool chat feature. The best part is, you don't even need an iphone or anything, you can just use the chat in the side of your gmail.
I have spent a lot of time trying to get everything working, and have found some other useful things. The one I will talk about now is Voice Central Black Swan. This is a web app, so you don't have to go through apple, just go to their page through safari after you sign up and it will tell you how to make it into an app. I don't think Black Swan is the great, because it doesn't have push notifications and it has adds, but it does one thing that the google web app does't. Black Swan lets you choose which phone you want it to call. For all you iPod Touch users, you now have a way to call people without using the GVMax chat work around.
Point of the story is that if you have Google Voice you can make all the calls and texts you want for free, it just takes some work. There are other ways to use it, this is just my preference. If you don't have it and are a student click here and get an invite within 24 hours, if not click here and wait. Good luck!