Stanza is a free application that lets you read electronic books on your iPhone. Its an excellent value, albeit with a no-frills approach that stops short of handling DRM-protected content and docs with heavy formatting or images.
Stanza provides a comfortable, highly customizable reading experience, and you can quickly change text size (with a slider in the settings, or using pinch and reverse pinch), adjust line and margin spacing, and choose from many different fonts. You can even pick your own text and background colors, in case you want old-school, CRT-style green on black. You can flip through chapters, rotate portrait or landscape, and search through text. Stanza also lets you leave multiple bookmarks and always remembers where you last left off.
It handles a wide variety of non-DRM formats (including Amazon Kindle, Mobipocket, Microsoft LIT, PalmDoc, and more), but PDFs and HTML dont always work quite like youd expect, since Stanza strips out images and formatting. Overall, this is an easy-to-use and useful app for anyone who doesnt already have a DRMd e-book collection, as Stanza makes it easy to download a ton of public domain content from its Online Catalog section (everything from Walt Whitman, Edith Wharton, and George Orwell to Kurt Vonnegut, Cory Doctorow, and H.P. Lovecraft). If youre still regretful about your lazy teenage years, youll especially like the High School Reading subsection--so you can download and finally finish reading Moby Dick and the Great Gatsby.