Its not big at all its about half the length of your hand when closed. Sure you open it up when using it for me size is about how big it is in the pocket etc.
Its a great phone it has a decent 5mp camera, you can run Route 66 sat nav on it with the internal gps or tomtom with a bluetooth external one (nokia maps is shite) and can use it as mp3 player for when you go for a run in the morning or whatever. It even surfs the net on your home wireless network. I've got no end of shit on my just download it all off torrents and sign it yourself with the sign tool. ( you have to have the certificate made to your IMEI first)
People moan about the battery and sure as a phone battery life its not the best but would your laptop be that great? For all the things it does its pretty good going. Those who get it with branded software/markings won't be able to upgrade to the latest firmware which patches bugs and improves features so do what i did and remove it with the tool and put the generic Nokia one on. That way you don't have to wait for o2, Orange or whoever to authorise the update, if they ever do.
I have no issues with mine going wrong.