Originally Posted by
eliddell VirtualDub is a free Windows-based editor for .avi files. Its cousin VirtualDubMod has a near-identical interface and also handles .mkv and .ogm . If you're starting with a .3gp file, you may have to convert it before you can use this software--I'm not familiar with the internal details of the format, so it might be yet another version of mpeg4+avi, but I wouldn't really bet on it.
VirtualDub can certainly be used to split files, but it will not automatically divide a file into chunks of a certain size. In order to use it for what you want, you'll have to select the part of your video file you don't want in the current 40MB chunk, select Edit > Delete, and then save the remaining video with appropriate encoding settings--and then start all over again to get the other four chunks. And it might take more than one try to get the exact file size you want.
You will have to use a video editor of some sort to do the splitting if you want to end up with smaller playable video files, though--a straight file-splitter won't do it, because most video codecs place vital information at the beginning and/or the end of the files they create.