It will barely even be comfortable to try and read text off the display and web browsing will have to be very minimal, you'll be scrolling everywhere because there is so little screen real estate...
As an N800 owner, I'd have to say 4.3 inch 800x480 browsing is a lot more usable than you seem to imagine. It's not going replace my desktop, but the majority of website I frequent are perfectly usable, even for extended periods. Even around the house you can surf in situations you normally wouldn't (like on the toilet, or when you're "watching" reality television), and a pocketable device is obviously preferable to carrying around a laptop when venturing outside if using webmail, checking threads, reading the news, uploading photos or social networking are all you need to do. In fact, I'd say the only things missing from the N800 are gaming controls, and enough power to play videos without re-encoding them.
I realise that running Beryl on the Pandora may be pushing things a bit too far (although
Compiz does appear to be available on ARM), but it doesn't seem too much of a leap of imagination to think some of the things in in the video of it running on "a shitty laptop with a very slow CPU", like the zooming, and flicking between screens without having to have a task bar, could make even better use of the Pandora's screen. From what I could find (
1,
2), the Pandora appears have a better spec. than the iPhone, and that seems to be able to run a fairly slick interface.
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