[murraypaul]

Stanza for iPad has now been released. This has built-in support for several free ebook sites, including Gutenberg, and you can download ePubs into it without any support from a PC, although it is a bit fiddly. I've found two ways so far.
In each case, navigate in Safari to a page with a link to an ePub file, and click-hold on the link until the menu appears, choose copy.
a) In Stanza, choose Get Books, Shared, Edit, Add Book Source
Enter something for the title, and paste in the URL you copied. The book will be downloaded, but will have the file name for a title, rather than the book title.
b) In GoodReader, choose Web Downloads, Enter URL
Enter the URL you copied.
Choose Manage Files, click the file you downloaded and Choose Open In, Stanza.
The book will be transferred to Stanza with the correct title.

[Edit: You can speed up the second method by using the GoodReader browser rather than Safari, then it is just a matter of clicking on the file you want and GoodReader will download it.]