So Anil turned me on this morning to a new Push-To-Talk app called Visual Communicator for the Series 60 phones and though he and I couldn't get it working because Telefonica's network sucks, here in the office I had one of the other 3650 owners try it with me and guess what? It actually works great!
Unlike FastChat which you need to sign up for a monthly fee, and Buzz2Talk which takes a bewildering amount of effort to sign up for a FreeWorldDialup account, this app is actually simple and relatively cheap at only $9.99 to buy and use indefinitely. The way it works, as well, is incredibly well done.
You first install and start up the app, it asks you if you want to have a monitoring service start up automatically. When that is started, it monitors incoming SMS messages for special "chat" messages from fellow VC users. So when you want to chat, you go into your VC app, and it displays all the people in your own address book (which is great - no need for a separate set of users) and when you choose the option to start the chat it sends off an SMS to that person to start. On the receiving end, the SMS comes in and the app starts up immediately "Do you want to chat with Russ?" and when you say yes, that's when you're connected to the Internet via GPRS. Whether it's pure P2P or needs some additional server, I'm not sure. But it seems to work pretty directly.
After that you simply hold down the green key to record your message, which it then compresses and sends and with in 5-10 seconds it plays on the other phone. Now, I'll admit, 5-10 seconds is a *long* time. However, it WORKS which is the coolest part, and out of the services I've seen so far, this definitely is the easiest to get up and running so far.
The app has some other features like text chat and sharing pictures which I didn't use yet, but the most important part seems to work as advertised. I'm definitely going to have to pony up the $9.99 for this well done app.