How to use GPS navigation using internet data plan on a windows mobile phone?

I have unlimited data plan on my phone. I am willing to buy any software allowing me to use GPS navigation on my phone utilizing my data plan. However I am not aware of any software of that kind. (I don’t want to buy a GPS receiver)

Here’s the info:
Phone – HTC Touch
OS – Windows Mobile 6
Unlimited internet data plan

Tagged as: gps receiver, info phone, internet data, os windows, unlimited internet