Google has been working hard to differentiate itself from other web services that try to “lock” their users into their services by making it hard to export data out. Google users can export data from many Google sites using Goolgle Takeout, an export service that lets people download their data. There's no question that keeping a local copy around may prove useful, in case something catastrophic happens (to Google's service), or if your account is disabled/deleted for some reason – any reason.
Google Voice is the latest service that you can export from, thanks to Takeout.
Ubergizmo, Google Voice personal data can be exported
