Virgin Mobile offers a great $25/month plan for unlimited data, text and web with 300 talk minutes with no contract to sign. This works great for me, as I generally just have short phone conversations. However there are of course times when I might get stuck on the phone for an hour or so. Below are a few extra steps I took to help get around the 300 minute limit without spending any more.
First, I ported my number to Google Voice(GV). GV has a lot of features, but the key feature is being able to indicate where to forward calls to when your phone number is dialed. For example, when my GV number is called, it is then forwarded to my mobile phone number.
Secondly, I setup GV to forward to Google Talk within Gmail. Im often in front of a computer, so this way I can easily make and receive phone calls for free without using my cell minutes or using a different phone number.
Lastly, to take it the extra mile, what about a VOIP call when you are on your cell phone in order to avoid using your minutes? Might as well use that unlimited data plan. Turns out that there are a few extra steps here, however it is relatively easy to setup. I use a Gizmo5 SIP account for this and I won't go into the details here, but there are plenty of posts on the web describing how to set this up. Keep in mind though that the call quality of this often does suffer based on the quality of the data connection.
If you sign up for a Virgin Mobile account, feel free to use the Kickback Code IYFUMN7I for an extra 60 minutes of talk time.