Update - Get Down with Download managerThis is a firefox extension.
Online FLV Converter : Download online videos direct to PC / iPod / PSP. It's free!
The service lets you submit a URL. The site will extract the video and decode it. You can then download later for personal viewing.
Ok lets say you might want to be a bit more discrete.
It's going to cost you a bit but well worth it. This thing is like magic. It captures everything in the background so you do need to have a little focus to clean up when your done surfing.
Applian Replay Media CatcherVersion: 2.10.00.00
The Ultimate FLV & MP3 Capture Tool
Record all kinds of FLV format Flash Videos.
Capture streaming MP3 files.
Automatically names songs and video files.
One click recording.
MP3 tag editor.
Works great for hard-to-capture sites using RTMP protocol.
Free Trial! - $40 to buy
Another online capture solution. Again free, my guess is not for long.