How to remove the timestamp from keychain camera video
The cheapest and easiest way I've found to get onboard video footage would have to be the 808 Keychain camera. Anything and everything you need to know about these great little cameras can be found here. While the quality isn't the best, it's good enough and until I save up the $380 to buy a GoPro HD, these $20 cameras are great to experiment with. By default video from the keychain cam includes a date and timestamp overlay that is encoded with the video. Sometimes that's ok but other times I'd prefer a nice clean image without the timestamp. There's a VirtualDub filter available here http://www.aircommandrockets.com/md80clone.htm direct download here. This page also has instructions how to install and use the filter. I'll go into a bit more detail including compressing the output and optimal settings for uploading to YouTube. The screenshot below shows a still image showing the original footage next to the version with the filter applied in VirtualDub. All the filter settings have been left to the default values. Note the overly blue haze across the top of the screen is because I filmed this through the blue tint at the top of the windscreen driving to work. You can see from the still image, it does a pretty good job. How about for a moving version. To apply the filter to the video, in VirtualDub;
Video, Filters (Ctrl F)
Add, Scroll down and select "Timestamp Remover", click ok
The default settings work fine, click ok again.
The source video window on the left has the timestamp where the processed version on the right has no timestamp.
Now if you you were to select File, Save as AVI...(F7) then the processed version would be saved as a rather large, uncompressed AVI file. For the source quality coming from the keychain cam, a bit of compression isn't going to hurt. One codec I like to use is the Xvid codec. If you don't already have it, grab it here. Back in VirtualDub;
Video, Compression ( Ctrl + P)
Select Xvid MPEG-4 Codec
Configure, if there's a button labelled 'Target quantizer', click it to change it to 'Target bitrate (kbps)' and enter 900 in the input field.
Click ok, then ok
Experimentation will go a long way here in figuring out what's best. These settings are merely a reference point to get started. 
December 15th, 2010 - 21:09
Can it keep recording constantly and dump the earliest footage automatically as memory fills up? If so it would be good as an evidence camera in a car.
December 15th, 2010 - 22:09
I’ve thought a bit about that. Power it from the car, have it start auto-recording as soon as you have power and have a rolling memory window dropping the last 5 minute blocks at a time.
December 16th, 2010 - 08:10
Yep. I reckon that’d be ace. I assume it has about as much image detail as a basic video camera of old, so it should be usable. Is it really $20? I’ll buy two – one for the front and one for the back.