This is quickly rising in my list of e-book sites and I'm thinkin it's latched on to the number two spot and with just a few improvements it could become my site of choice.
First, Lot's of good books in e-pub format with reasonable pricing, if you have a Sony reader or e-pub compatible device you have to love it.
I have to agree with some of the earlier comments regarding the search engine and the site being somewhat confusing. My first look through the site I was convinced you could not download books - just read the first chapter or purchase and read on-line, or read it on a mobile device - but that is definitely not the case.
As far as downloading books - I set my browser "FireFox" to download e-pub files into my Sony reader library. To my surprise that's exactly what happened when I downloaded my first book - right into the Sony e-book library. (I did not have to download it first into Adobe's ADE library and then export it.) I then downloaded it into my reader without a hitch.
I'll repeat myself - if you have a device that reads epub files - you really should check out this site.
good job!