RIM's new BlackBerry Z10 isn't official yet, but a tipster on Twitter has apparently already found one in a UK store. "CravingBattery" posted a picture of a black Z10 at a Phones4U store, where they look like they'll be on sale soon. We'd previously heard that the Z10 would be launching in the UK on the 30th, with the phones in stores on the 31st, based on a Vodafone leak. While we've only seen a picture of the black phone, he's said Phones4U has the white one in stock as well. We followed up by phone with the store he mentioned and were told dummy units would be on display until 5pm, when the phones would go on sale.

In followup tweets, CravingBattery said that Carphone Warehouse, another UK retailer, would be putting demo units on display tomorrow. He also corroborated what we've heard about the white version of the Z10: it sounds like it won't be showing up in some places until mid-February. "Spoke to Carphone, they've only got black until the 15th Feb., then the white model." Our last tip indicated that the white Z10 would launch first at Phones4U.

Update: We've since received another image of the white Z10 from Phones4U — though we can't post it here — with a tip that it'll be in stock tomorrow.