I recently purchased and unlocked a Storm and am using it on T-Mobile. I was wondering if the Visual Voicemail can be made to work with the provider I am using, and if so, how do I go about it?

Are you asking if the VZW VisualVoicemail will work on the Storm you are using on TMobile?

If so, I would suggest looking into a 3rd party version such as YouMail, and the associated apps that hook into the YouMail account (VyMail or Visual Voicemail Plus).