Ah, good, glad to hear it was there after all. I downloaded three versions of
VirtualDub, and all of them had Resize included.
However, it is available here:
http://neuron2.net/resize.html
I've long used v1.5.1 and have not had reason to change in years. I have recently downloaded and installed v1.7 because of some advanced integration with NeatVideo, but my primary day-to-day work is still done in v1.5, at least for now. I'm not fond of the changes made to some of the functional aspects of the program in v1.7, but it does have some newer filters added by default. If I'm not mistaken, there were a few new resizing filters, and other filters. Right now
virtualdub.org has v1.8-stable and v1.9-experimental available too, if you're in the mood to "play around".