I’m generally not a fan of using an app that re-works a website to be more “mobile-friendly.”
Wikipanion is the exception. It makes browsing Wikipedia articles easy and fast from any iOS device. Since I co-host the world’s most popular Wikipedia-related podcast, you know I’ve played with numerous apps in this category
(While I’ll be looking at the iPad app in this review, the iPhone app is just as useful and well-designed. Note that Wikipanion is not an universal app as of this writing.)