I've been using the Motorola Droid free Navigator app by google for sometime now, so my impression of it is actually pretty good.  It gave me what i need, and get me to where I wanted to go.  But how does it stack up with the AT&T's Navigator on the iPhone you may asked?

Someone at Mobile crunch just did a nice compare. (Please note the, AT&T Navigator is not free, but $10/month )

Here's a quick comment from Todd Witkemper, from Telenav:

In general, here are a few differentiators that TeleNav products provide that Google Navigation does not have:

 

• Proven map data that is consistently updated (I've read multiple reviews of Google Navigation where the reviewer received incorrect routing)
• Online preplanning/account management
• A real person's voice for majority of audio commands (vs. text to speech computerized voice)
• Proactive traffic alerts with one-click rerouting (you don't have to change views to see traffic updates)
• Real-time gas prices, weather, WiFi hot spot listings, commute alerts and movie listings/ticket purchasing (movie info on AT&T Navigator 1.8)
• Route style options like avoiding HOV lanes and toll roads

 

• Location-sharing

 

TeleNav also supports more than 500 devices in multiple countries.

 

via: mobilecrunch.com