Rusky and Andygates, thanks for the update. I have indeed experienced PDF on small devices such as my iPAQ PDF (work issue, 2003 vintage and still going strong), and its not much fun. As you say, the reflow business is pants. My Tomtom is capable of displaying some sort of ebook, if its epub compatible I might try a conversion just to see. Not that I'd use the Tomtom as an ebook reader except in extremis.
I was even musing over getting a Archos 7, or maybe an Eeepad, and using it as an ebook reader as one of its uses. However the reliance of such devices on WiFi as their only internet access rather screws them for me, as I spend most of my time in more rural areas when away from home. One of the reasons I sold my EeePC was because relying on Wifi for access isn't really workable for me. Whilst I suffer dreadfully from gadget hunger, I do want one "flat thing with a display" to perform several tasks. At present I have a full size laptop, and a cheapo smartphone that does at least allow me to collect emails, and rather limited web browsing.
Next problem with those is working out the problem caused by Virgin seeming to have decided that whenever I download an email, it deletes it from the server, even though the portable devices in question are configured not to do that... Grrr. There are only supposed to delete from the server when they make it to my main PC!