the author of this app says:
Good Reader app for iPad! If you need to read huge PDF, or TXT files, you've come to the right place. Faithful users of GoodReader have reported flawless performance with files over 1 gig in size; but that's only one of the many features that makes GoodReader the best app of its kind.
Within moments of downloading GoodReader, you'll be transferring files directly from your computer over a Wi-Fi connection, from the Internet or from email attachments. It also easily integrates with MobileMe iDisk, box.net, MyDisk.se and other popular WebDAV servers, and also with non-WebDAV services like Google Docs and Dropbox.
Requires iPhone OS 3.2 or later.