Unpleasant situation: you just sent a large document (say, 50 MB), but then you needed to make changes to a couple of paragraphs or lines. Re-forwarding such a file is often problematic.
If you regularly have to work with large documents, send them by e-mail and at the same time you use dial-up access, you should pay attention to the free PatchOnClick program (Windows 98, 98SE, ME, NT4, 2000, 2003, XP, Vista).
The way PatchOnClick works is simple. You specify the source and edited files to the application. The program compares them and creates a patch that will make the necessary changes to the file. Blog freewaregenius.com provides data on the effectiveness of PatchOnClick. If the original Zip archive weighed 69.1 MB, and the edited 73.1 MB, then the patch will weigh about 576 KB. Agree that it is easier to email half a megabyte in dialup than 73 MB. PatchOnClick is effective in working with documents and archives, but less useful in the case of videos and tables.
The main disadvantage of PatchOnClick is that on both computers (where the patch is created and where it will be applied) this program must be installed.
PatchOnClick [via freewaregenius.com]