I hate, hate, hate getting stuck in traffic, especially on the freeway (where you're usually trapped until the next exit). That's why I always drive with a GPS that can receive live traffic updates and steer me clear of congested areas.
Or a GPS app. CoPilot Live, MobileNavigator, and TomTom are among those that offer a live-traffic option, but all three charge you extra for it--usually on a monthly or annual basis.
Magellan RoadMate used to be the same way, but now, with the release of version 1.3, RoadMate offers free live traffic updates for life. I'm not saying that elevates it above all other iPhone GPS apps, but it's definitely a hard perk to ignore.
Another improvement in RoadMate 1.3: location-based promotional offers. So if you're driving near, say, a Big Boy and there's a coupon available, it'll pop up onscreen--and give you the option of routing to the location or saving the deal for later.
The app has also been updated to support iOS 4, which gives you multitasking, continued navigation during phone calls, and uninterrupted voice guidance even while you're using other apps.
Until tomorrow (Dec. 1), all three versions of RoadMate--North America, USA, and Canada--are on sale for $44.99, $34.99, and $29.99, respectively. (If you've already purchased RoadMate, the update--including the lifetime traffic information--is free of charge.)