[alex_d]

Ha, I love it when someone asks "what features can i add?" And I love it even more that I know that you're the kind of guy to actually implement them.

Here are some things that I know people want given my experience gathering feedback for pdfrasterfarian:

Working with images as input (something I never got around to doing myself):
Lots of people have folders of images of scanned books or comics they'd like to collate. Part of this feature is the ability to process double-page scans. Ie, you first split the scan down the middle (down a user-adjustable line) and then again if you're converting into landscape mode. This was one of the most popular feature requests I received.

Some minor stuff:
When a user selects a file, the format (pdf/djvu) can be selected automatically based on the extension. Also, when a user selects a profile, the file extension (eg .lrf) MUST be added automatically. (Otherwise the device won't open the file and the user won't know why.)

Some more minor stuff:
Try to add explanations for your options, particularly on the "customize" page. Even I am not sure what some of the things mean, and you're really robbing your users by taking away configurability (either completely or just in practice). A good way to add explanations is a box at the bottom whose contents change depending on where the mouse points.

Some more minor stuff, continued:
When you give people configuration options, and even if you add good explanations, there should be a way to preview the result.