iOS 6 Safari
Aside from the speed boosts you'd expect from a refreshed browser, Safari for iOS 6 brings with it a number of updates, two of which centre around iCloud.
The rather poor and half-hearted Reading List feature, which saves web pages for you to read later, now works offline. This is a major improvement, although because Safari pulls down the entire document, saving it takes longer than sending a web page to the likes of Instapaper or Pocket. However, Reading List content syncing across iCloud now makes it a potential alternative to a bespoke read-it-later app or service.
Another great new feature is iCloud tabs. Once activated, this enables you to see open tabs on other devices using the same iCloud ID, including Macs running the latest version of Safari.
There are also a couple of interface changes: tap-holding the back button now brings up the history list, and the iPhone and iPod touch now have a full-screen mode, although it's only available in landscape orientation.
iOS 6 Mail
Mail's updates in iOS 6 are relatively small but are nonetheless very welcome. First and foremost, Apple brings its VIP feature to iOS. This enables you to define certain people you communicate with as VIPs and have their emails arrive in the VIP inbox. Ultimately, it's a pre-defined smart mailbox, but it's handy if you're drowning in email and don't want to miss crucial messages from specific people.
Elsewhere, Apple now enables you to insert photos into emails and has included pull-to-refresh with a cute gloopy refresh icon. Additionally, you can now set signatures on a per-account basis, rather than being forced to use the same one for all of them.