I've seen a couple of deals on the Dialaphone site that look to be market-leading deals. They're offering the N97 free on a £55/mth 12m Vodafone tariff, meaning that you only pay £660 over the length of the contract, minus Quidco or Top Cashback £50. You also get 1200 minutes, unlimited texts and unlimited mobile internet. Seeing as it's available for £499.99 from Play.com SIM free I think this is a good deal.
I appreciate that might be a bit pricey on a monthly basis, but they're also offering it free on a £35/mth contract, which is the cheapest tariff I've seen this being offered free on. It is a 24mth contract however.