So yesterday I expressed how useless the Zoom 1.2 filter(plug-in) by Donald Graft And Avery Lee for VirtualDub is. 999x999 wasn't a modern resolution. However, there is another tool called the 'motion filter', which allows higher resolutions, and as a bonus, it also allows rotation and panning.
Of course, this is excellent for non-elaborate screencasts in which one needs a fast zoom to a part where one forgot to do it in the screen-capturing session with the excellent tool ZoomIt.
It is always a great idea to rely on various tools as back-up mechanisms for features. In this case a zoom missed in production(with ZoomIt) can be corrected in post-production with VirtualDub and this excellent motion filter tool by Ben Greenwood.