How can I use google voice on the computer but not from gmail?

I am trying to use google voice on my computer, which I see you need gmail to make calls out of. I am not a gmail user, so how can I somehow use the feature of calling from my computer without being inside of gmail?

When I go to sign up for a gmail, which I already have an old one, it prompts me this

You’re currently signed in to your remington.guest@me.com Google Account.
If you complete this form, you’ll be adding Gmail to this account, and your Gmail address will become your primary account username.

If you would prefer, you can create a separate Google Account for Gmail. You’ll be logged out of xxxxxx@me.com and then be able to create your new account.

the thing is i don’t want to create a new account because I have all of my google applications linked to my me.com account. Is there any way around this?