I've just been using Portable Offline Browser for my first serious project, and I'm very pleased with it. Excellent job!
I do have a suggestion, though. I've downloaded a documentation website and have been using it for reference purposes. There are a few topics that are of special interest to me, but they are buried in the hierarchy of the site, and I often forget exactly how to navigate to them. Even when I do remember, clicking 7 or 8 times to get back to the topic I want is a chore.
Unfortunately, the site map is not helpful here, as the page URLs are all of the "index.php?article=xx" variety, and convey no information about the contents of the topics they link to.
If there were a way to specify favorites for a site, I could build a custom list of pages for each site with only the topics I was most interested in. Ideally, these would appear in the Projects view under the icon for the project, so I could get to them with one or two clicks.
Thanks for a great program!