I got it from... Vodafone! I got it through work on the BES (Business Education Sector?) 2 years contract for £400 (without line rental - that is seperate...)
I've been reading up on the E90, and maybe it would be best until Nokia rolls out the new version which doesn't have the major 'buzz' sound problem (before a connection) and maybe also for them to recognise the 'keys scratching the inner screen' problem too!