Sorry if i seem to be pushing my videos on this thread, but this is what can be done using Bandicam (free program from the net). Although the free version only gives you 10 minutes of recording time at a go, you can still put together a good video with it. Just record the replays, and then pop them onto Windows movie maker. With some practice, you could be doing great videos in no time. Have a look at this link to see what i have done using Bandicam.
http://www.wgt.com/forums/t/214020.aspx
Bandicam can do downloaded from here:
http://www.bandicam.com/downloads/
PS: If you have the time, could you please vote? lol, cheers.