Ubuntu, Calibre, Blackberry w/MobiPocket - a good experience

I have just had a good experience on my Aspire One netbook and eBooks. I don't generally buy ebooks just because they are as expensive or more so than the equivalent paper book. But, I have just tried an ebook system with Ubuntu, Calibre and MobiPocket on my Blackberry. It was quite good. I downloaded  free ebook in epub format, converted it with Calibre, attached the Blackberry and set it to look like a USB drive. Clibre then detected it and sent the converted book to the device. Everything worked well and I'm able to read the book on the phone. Pretty neat if you ask me.