Wheel Bearings

Over many years of car ownership of various sorts, the problem of knackered wheel bearings raises its head from time to time.
You hear the whirring noise, you know what it is but you don't know which wheel it is. You know if you turn the steering wheel one way, it gets quieter. I have never worked out if you turn the wheel to the left (for instance) which side bearing this would refer to.
And don't all say that I should try lifting and spinning the wheel, because on my Disco, it doesn't work. The only way you can tell is to take the wheel off, take the half shaft out and back the brake pads off. Then you can see if theres any slack.
Whats really annoying, is that I have just replaced both rear bearings and I don't think I got anything wrong, so its probably a front bearing.

Any definitive opinions out there?

cant you just jack the wheels up and move them forwards and backwards and see if there is any laterally play, rather than spinning them, which is harder to detect

Thats the point. With everything connected, there doesn't appear to be any movement in any direction. Once you get the half shafts out and the brakes backed off then any slack will show up. But even then, a noisy bearing might not show any slack until its worn more.

I bought some chassis ears for listerning to faults so I could locate them. Found a bearing fault and idler pulley failed too. 6 sensors which you can place on your car so you can locate the noise from which sensor detects the loudest noise.

chassis ears, Vehicle Parts Accessories items at low prices on eBay.co.uk

example noise of a failed bearing:

[nomedia="http://www.youtube.com/watch?v=-isenbghOOI"]YouTube- Land Rover Freelander 1 failed vcu support bearing[/nomedia]