Google Nav is pretty friggin awesome. I had a TomTom for the first year I lived in NYC and the last year I owned a car, and Google Nav was comparable on all fr

Google Nav is pretty friggin awesome. I had a TomTom for the first year I lived in NYC and the last year I owned a car, and Google Nav was comparable on all fronts, as demoed in rental cars up and down the Eastern Seaboard since then. Notable downsides include battery life and built-in mounting options. Notable upsides include no upfront purchase, free updates, constant updates, better information density (pixels per meatspace volume, roughly), ease of ad-hoc "mounting" (e.g. next to the speedometer, behind the steering wheel), and automatic "straight-to-pocket-on-exit" theft protection. It's free, it works well, and it integrates nicely with other Android apps (notably Google Maps).