I use Google voice, just install and sign in using your Gmail account. Also, may try TxtTab. App that connects tab with android phone thru Bluetooth. Lets you send and receive txts on the tab, thru your phone. Works great with my bionic. Please be aware I have wifi only tab.
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Went from OG Droid to Droid Bionic. I'm just a little dizzy...
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If you want to use your Google voice for incoming and out going VOIP calls you can grab a handy little app off the market called GrooveIP it gives you every thing you need to make and take calls with Google Voice, for texting just use the Google Voice app from the market.
Sometimes you have to change the settings in Google Voice to receive calls just go to http://google.com/voice and change your Forward calls to: and make sure the only one checked is Google Chat that way it only rings the Voice account when your Voice number is called.
Hope that helps
you can send an email that will be received as a text message
Virgin Mobile: firstname.lastname@example.org