In order to delete Vlingo: Go to Settings -> Applications -> Manage Applications. Then, choose Vlingo and click Uninstall.
At this time, Vlingo cannot be uninstalled from Android devices that come with the Vlingo software pre-installed. This includes, but is not limited to, the Motorola Atrix as well as the Samsung Galaxy S2 and S3 models that have the Samsung voice applications powered by Vlingo (i.e. Voice Command and Voice Talk) pre-programmed on the phone.