Some apps which I use

Stanza (free) - awesome ebook reader, browse and download books from the application itself. There are several catalogs to choose from, from paid sites to free ones like project guttenberg. Downloaded several interesting books for free from Random House Free catalog, including Terry Brook's A Magical Kingdom For Sale - Sold, I highly recommend this book.

Convertbot (free) - units and currency conversion tool

MoneyTracker (free) - simple money tracking application

To Do (free) - simple to do list

RssRunner (free) - simple RSS reader

Stanza can do this.