Sharp-eyed reader and frequent commenter Zane tipped me to this. Here’s a mashup from Mike Purvis, co-author of Beginning Google Maps Applications, that lets you see and compare Tele Atlas and NAVTEQ data sources. So if you have been wondering whether to buy a Garmin GPS (with NAVTEQ data) or a TomTom GPS (with Tele Atlas data), now you can check them out before you buy!
I don’t know how recent the map data is, but I’m assuming it’s fairly
current. It shows a 2007 copyright date for both providers. According
to Mike, these are the "API vs. non-API tiles that Google makes
available." Here’s a post that explains it all in some detail.