knocking sound when in neutral, HELP!!! Options

[undasighted]

I noticed last night that there's a steady knocking sound coming from under the front axle, but it doesnt do it when I'm speeding up or braking. Only time it makes the sound is when the clutch is in or it's in neutral. It doesnt seem to be driving any different, but I'm worried that it's one of those problems where things either slowly deteriorate or start making a noise then go suddenly.

Please help!

[malecrod]

My first thought is also the release bearing. I had the similar problem only at idle but mine also had a problem where the release bearing springs was coming off of the release fork making the clutch pedal get stuck sometimes. I replaced the release bearing with toyota/OEM one ($45)with grease on it and the rattling is gone.
Release bearing = throwout bearing.
Also make sure there is no loose bolts somewhere underneath car.
Replacing the release bearing/throwout bearing is similar to a clutch job since you have to remove driveaxles and the transmission to get to it. it took me two days to complete for a first timer(a total of maybe 14hours). I would say it was more of a time consuming job to do. Not necessarily hard. Just remember to label all bolts and nuts in several plastic bags and you should be fine. Oh, a transmission jack is a must or at least makes transmission removal and reinstallation easier.
G/L