To the OP, bear in mind that the internal GPS chip on the Verizon 8330 will not currently work with 3rd party applications. It currently only works with the BBMaps and VZNav.
amAze GPS is my favorite free turn-by-turn navigation app. The UI is beatiful but godawful slow. Once you get past entering your destination and actually start navigating, it works great. It's free forever.
Nav4All is my 2nd favorite "free" turn-by-turn navigation app. It covers the most countries of any navigation app I've seen. The UI is quick but outdated, looking much like my 10 year old nav system. Nav4All is only free through year-end 2009.
Google Maps and BB Maps provide free, basic step-by-step navigation. They will show your location on a moving map and will show you the next step/turn. But after you've made the turn, you have to press a key to advance to the next step.
All BlackBerry navigation apps use a data plan.
Click over to the GPS & Mapping forum for more discussion about navigation software for your BlackBerry.