In a nutshell Trunk is a personal wiki. It gives you the tools to create interconnected web pages using the simple Markdown language as well as the more complex HTML tags. Anyone can create these pages using WikiWords, and pages can store links to other pages or external web sites, as well as formatted text. This simplicity belies the power of Trunk, though, as it represents a unique way for users of the iPhone to manage information.

This application is a singing book designed to entertain a young child. However, it is much more than that. It has multiple languages, instruments and recording support, turning it into a great educational tool.

When connected to the Internet you can use Wikipedia Mobile to search Wikipedia for articles, which can then be saved to you’re iPhone for offline viewing. Pages retain their original formatting and can be searched for words or phrases, but the app has no built-in zoom, nor does it offer bookmarking or annotation capabilities. Regardless, it’s a great way to create a library of articles conventiently available whether you have connectivity or not.

Linguo is a good combination translation front-end and phrase dictionary with audio phrases.