I bought this battery for £3.99 and got it the other day. They've pushed the price up to 5.99 but it now ships from the UK.
Despite not expecting much, it seems to last pretty much the same as the stock battery! Screenshot below (I'm a moderate user, heavy use on hour long commute and little use in the day).
Is the same size as the stock batt and it says 2000mah on the battery (although that is likely to be a lie )
Edited by jpwjpw, 18 January 2012 - 12:50 PM.