turn the engine on but remain stationary, can you hear the noise? Put the clutch in, can you hear it now? Is the noise only present during acceleration and decelleration or can you hear it if you free wheel? (rolling along with the clutch in or the car in neutral) Also check if the noise co-incides with the cooling fan coming on as the engine temperature rises and/or with you having the internal fans switched on.
If the noise is present with the engine on but the car stationary and in neutral then you can rule out gearbox issues, clutch bearings and wheel bearings, leaving fans and pulley assemblies.
If the noise is present when the clutch is pushed in then the likely answer is your clutch bearing.
If the noise is present when the car is moving, regardless of free wheeling then it is probably a wheel bearing.
If the noise is present all the time then check to make sure that you have the heaters/internal fans off.
If the noise only comes as the car heats up, check to make sure that the radiator fan is turning freely and not obstructed.
From what you have said in your original post, the wheel bearings would be the first culprit but as I can't hear the noise....
Best of luck
Alcopup
August 2007